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<title>Date</title>
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<center><h1>Module <a href="type_Date.html">Date</a></h1></center>
<br>
<pre><span class="keyword">module</span> Date: <code class="code">sig</code> <a href="Date.html">..</a> <code class="code">end</code></pre>Date operations.
<p>
This module implements operations on dates.
A date is a triple (year, month, day).
<p>
All the dates should belong to
<code class="code">[January, 1st 4713 BC; January 22th, 3268 AC]</code> (called the Julian period).
An <code class="code">Out_of_bounds</code> exception is raised if you attempt to create a date
outside the Julian period.
<p>
If a date <code class="code">d</code> does not exists and if <code class="code">d_bef</code> (resp. <code class="code">d_aft</code>) is
the last (resp. first) existing date before (resp. after) <code class="code">d</code>,
<code class="code">d</code> is automatically coerced to <code class="code">d_aft + d - d_bef - 1</code>.
For example, both dates "February 29th, 2003" and
"February 30th, 2003" do not exist and they are coerced respectively to the
date "Mars 1st, 2003" and "Mars 2nd, 2003".
This rule is called the coercion rule.
As an exception to the coercion rule, the date belonging to
<code class="code">[October 5th, 1582; October 14th, 1582]</code> do not exist and an <code class="code">Undefined</code>
exception is raised if you attempt to create such a date.
Those dropped days correspond to the change from the Julian to the Gregorian
calendar.<br>
<hr width="100%">
<br>
<a name="1_Datatypes"></a>
<h1>Datatypes</h1><br>
<pre><span class="keyword">type</span> <a name="TYPEt"></a><code class="type"></code>t </pre>
<div class="info">
Type of a date.<br>
</div>
<br><code><span class="keyword">type</span> <a name="TYPEday"></a><code class="type"></code>day = </code><table class="typetable">
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Sun</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Mon</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Tue</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Wed</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Thu</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Fri</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Sat</span></code></td>
</tr></table>
<div class="info">
Days of the week.<br>
</div>
<br><code><span class="keyword">type</span> <a name="TYPEmonth"></a><code class="type"></code>month = </code><table class="typetable">
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Jan</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Feb</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Mar</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Apr</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">May</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Jun</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Jul</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Aug</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Sep</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Oct</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Nov</span></code></td>
</tr>
<tr>
<td align="left" valign="top" >
<code><span class="keyword">|</span></code></td>
<td align="left" valign="top" >
<code><span class="constructor">Dec</span></code></td>
</tr></table>
<div class="info">
Months of the year.<br>
</div>
<pre><span class="keyword">type</span> <a name="TYPEyear"></a><code class="type"></code>year = <code class="type">int</code> </pre>
<div class="info">
Year as an <code class="code">int</code>.<br>
</div>
<pre><span class="keyword">type</span> <a name="TYPEfield"></a><code class="type"></code>field = <code class="type">[ `Day | `Month | `Week | `Year ]</code> </pre>
<div class="info">
The different fields of a date.<br>
</div>
<br>
<a name="1_Exceptions"></a>
<h1>Exceptions</h1><br>
<pre><span class="keyword">exception</span> <a name="EXCEPTIONOut_of_bounds"></a>Out_of_bounds</pre>
<div class="info">
Raised when a date is outside the Julian period.<br>
</div>
<pre><span class="keyword">exception</span> <a name="EXCEPTIONUndefined"></a>Undefined</pre>
<div class="info">
Raised when a date belongs to <code class="code">[October 5th, 1582; October 14th, 1582]</code>.<br>
</div>
<br>
<a name="1_Constructors"></a>
<h1>Constructors</h1><br>
<pre><span class="keyword">val</span> <a name="VALmake"></a>make : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int -> int -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">make year month day</code> makes the date year-month-day.
A BC year <code class="code">y</code> corresponds to the year <code class="code">-(y+1)</code>.
E.g. the years (5 BC) and (1 BC) respectively correspond to the years
(-4) and 0.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALlmake"></a>lmake : <code class="type">year:<a href="Date.html#TYPEyear">year</a> -> ?month:int -> ?day:int -> unit -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Labelled version of <code class="code">make</code>.
The default value of <code class="code">month</code> and <code class="code">day</code> is <code class="code">1</code>.<br>
<b>Since</b> 1.05<br>
</div>
<pre><span class="keyword">val</span> <a name="VALtoday"></a>today : <code class="type">unit -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Date of the current day (based on <code class="code">Time_Zone.current ()</code>).<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_jd"></a>from_jd : <code class="type">int -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Make a date from its Julian day.
E.g. <code class="code">from_jd 0</code> returns the date 4713 BC-1-1.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_mjd"></a>from_mjd : <code class="type">int -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Make a date from its modified Julian day (i.e. Julian day - 2 400 001).
The Modified Julian day is more manageable than the Julian day.
E.g. <code class="code">from_mjd 0</code> returns the date 1858-11-17.<br>
</div>
<br>
<a name="1_Getters"></a>
<h1>Getters</h1><br>
<pre><span class="keyword">val</span> <a name="VALdays_in_month"></a>days_in_month : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Number of days in the month of a date.
E.g <code class="code">days_in_month (make 2003 6 26)</code> returns <code class="code">30</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALday_of_week"></a>day_of_week : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEday">day</a></code></pre><div class="info">
Day of the week.
E.g. <code class="code">day_of_week (make 2003 6 26)</code> returns <code class="code">Thu</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALday_of_month"></a>day_of_month : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Day of the month.
E.g. <code class="code">day_of_month (make 2003 6 26)</code> returns <code class="code">26</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALday_of_year"></a>day_of_year : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Day of the year.
E.g. <code class="code">day_of_year (make 2003 1 5)</code> returns <code class="code">5</code>
and <code class="code">day_of_year (make 2003 12 28)</code> returns <code class="code">362</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALweek"></a>week : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Week.
E.g. <code class="code">week (make 2000 1 3)</code> returns <code class="code">1</code> and <code class="code">week (make 2000 1 2)</code> returns
<code class="code">52</code>. <code class="code">week (make 2003 12 28)</code> returns <code class="code">52</code> and <code class="code">week (make 2003 12 29)</code>
returns <code class="code">1</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALmonth"></a>month : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEmonth">month</a></code></pre><div class="info">
Month. E.g. <code class="code">month (make 2003 6 26)</code> returns <code class="code">Jun</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALyear"></a>year : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEyear">year</a></code></pre><div class="info">
Year. E.g. <code class="code">year (make 2003 6 26)</code> returns <code class="code">2003</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALto_jd"></a>to_jd : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Julian day. E.g. <code class="code">to_jd (make (-4712) 1 1)</code> returns 0.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALto_mjd"></a>to_mjd : <code class="type"><a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Modified Julian day (i.e. Julian day - 2 400 001).
The Modified Julian day is more manageable than the Julian day.
E.g. <code class="code">to_mjd (make 1858 11 17)</code> returns 0.<br>
</div>
<br>
<a name="1_Booleanoperationsondates"></a>
<h1>Boolean operations on dates</h1><br>
<pre><span class="keyword">val</span> <a name="VALcompare"></a>compare : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEt">t</a> -> int</code></pre><div class="info">
Comparison function between two dates.
Same behavior as <code class="code">Pervasives.compare</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALequal"></a>equal : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEt">t</a> -> bool</code></pre><div class="info">
Equality function between two dates. Same behavior as <code class="code">(=)</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALis_leap_day"></a>is_leap_day : <code class="type"><a href="Date.html#TYPEt">t</a> -> bool</code></pre><div class="info">
Return <code class="code">true</code> if a date is a leap day
(i.e. February, 24th of a leap year); <code class="code">false</code> otherwise.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALis_gregorian"></a>is_gregorian : <code class="type"><a href="Date.html#TYPEt">t</a> -> bool</code></pre><div class="info">
Return <code class="code">true</code> if a date belongs to the Gregorian calendar;
<code class="code">false</code> otherwise.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALis_julian"></a>is_julian : <code class="type"><a href="Date.html#TYPEt">t</a> -> bool</code></pre><div class="info">
Return <code class="code">true</code> iff a date belongs to the Julian calendar;
<code class="code">false</code> otherwise.<br>
</div>
<br>
<a name="1_Coercions"></a>
<h1>Coercions</h1><br>
<pre><span class="keyword">val</span> <a name="VALto_unixtm"></a>to_unixtm : <code class="type"><a href="Date.html#TYPEt">t</a> -> Unix.tm</code></pre><div class="info">
Convert a date into the <code class="code">Unix.tm</code> type.
The field <code class="code">is_isdst</code> is always <code class="code">false</code>. The fields <code class="code">Unix.tm_sec</code>,
<code class="code">Unix.tm_min</code> and <code class="code">Unix.tm_hour</code> are irrelevant.<br>
<b>Since</b> 1.01<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_unixtm"></a>from_unixtm : <code class="type">Unix.tm -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Inverse of <code class="code">to_unixtm</code>. Assume the current time zone.<br>
<b>Since</b> 1.01<br>
</div>
<pre><span class="keyword">val</span> <a name="VALto_unixfloat"></a>to_unixfloat : <code class="type"><a href="Date.html#TYPEt">t</a> -> float</code></pre><div class="info">
Convert a date to a float such than <code class="code">to_unixfloat (make 1970 1 1)</code>
returns <code class="code">0.0</code>. So such a float is convertible with those of the <code class="code">Unix</code>
module. The fractional part of the result is always <code class="code">0</code>.<br>
<b>Since</b> 1.01<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_unixfloat"></a>from_unixfloat : <code class="type">float -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Inverse of <code class="code">to_unixfloat</code>. Ignore the fractional part of the argument.
Assume the current time zone.<br>
<b>Since</b> 1.01<br>
</div>
<pre><span class="keyword">val</span> <a name="VALto_business"></a>to_business : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEyear">year</a> * int * <a href="Date.html#TYPEday">day</a></code></pre><div class="info">
Return the "business week" and the day in this week respecting ISO 8601.
Notice that business weeks at the beginning and end of the year can
sometimes have year numbers which don't match the real year.
E.g. <code class="code">to_business (make 2000 1 3)</code> returns <code class="code">2000, 1, Mon</code> and <code class="code">to_business
(make 2000 1 2)</code> returns <code class="code">1999, 52, Sun</code>. <code class="code">to_business (make 2003 12 28)</code>
returns <code class="code">2003, 52, Sun</code> and <code class="code">to_business (make 2003 12 29)</code> returns <code class="code">2004,
1, Mon</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALfrom_business"></a>from_business : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int -> <a href="Date.html#TYPEday">day</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Inverse of <code class="code">to_business</code> respecting ISO-8601.
Raise <code class="code">Invalid_argument</code> if the week is bad.
Notice that business weeks at the beginning and end of the year
can sometimes have year numbers which don't match the real year.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALint_of_day"></a>int_of_day : <code class="type"><a href="Date.html#TYPEday">day</a> -> int</code></pre><div class="info">
Convert a day to an integer respecting ISO-8601.
So, Monday is 1, Tuesday is 2, ..., and sunday is 7.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALday_of_int"></a>day_of_int : <code class="type">int -> <a href="Date.html#TYPEday">day</a></code></pre><div class="info">
Inverse of <code class="code">int_of_day</code>.
Raise <code class="code">Invalid_argument</code> if the argument $\notin <code class="code">1; 7</code>$.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALint_of_month"></a>int_of_month : <code class="type"><a href="Date.html#TYPEmonth">month</a> -> int</code></pre><div class="info">
Convert a month to an integer respecting ISO-8601.
So, January is 1, February is 2 and so on.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALmonth_of_int"></a>month_of_int : <code class="type">int -> <a href="Date.html#TYPEmonth">month</a></code></pre><div class="info">
Inverse of <code class="code">int_of_month</code>.
Raise <code class="code">Invalid_argument</code> if the argument $\notin <code class="code">1; 12</code>$.<br>
</div>
<br>
<a name="1_Period"></a>
<h1>Period</h1><br>
<pre><span class="keyword">module</span> <a href="Date.Period.html">Period</a>: <code class="code">sig</code> <a href="Date.Period.html">..</a> <code class="code">end</code></pre><br>
<a name="1_Arithmeticoperationsondatesandperiods"></a>
<h1>Arithmetic operations on dates and periods</h1><br>
<pre><span class="keyword">val</span> <a name="VALadd"></a>add : <code class="type"><a href="Date.html#TYPEt">t</a> -> Period.t -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">add d p</code> returns <code class="code">d + p</code>.
E.g. <code class="code">add (make 2003 12 31) (Period.month 1)</code> returns the date
2004-1-31 and <code class="code">add (make 2003 12 31) (Period.month 2)</code> returns the date
2004-3-2 (following the coercion rule describes in the introduction).<br>
</div>
<pre><span class="keyword">val</span> <a name="VALsub"></a>sub : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEt">t</a> -> Period.t</code></pre><div class="info">
<code class="code">sub d1 d2</code> returns the period between <code class="code">d1</code> and <code class="code">d2</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALrem"></a>rem : <code class="type"><a href="Date.html#TYPEt">t</a> -> Period.t -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">rem d p</code> is equivalent to <code class="code">add d (Period.opp p)</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALnext"></a>next : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEfield">field</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">next d f</code> returns the date corresponding to the next specified field.\\
E.g <code class="code">next (make 2003 12 31) `Month</code> returns the date 2004-1-31
(i.e. one month later).<br>
</div>
<pre><span class="keyword">val</span> <a name="VALprev"></a>prev : <code class="type"><a href="Date.html#TYPEt">t</a> -> <a href="Date.html#TYPEfield">field</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">prev d f</code> returns the date corresponding to the previous specified
field.
E.g <code class="code">prev (make 2003 12 31) `Year</code> returns the date 2002-12-31
(i.e. one year ago).<br>
</div>
<br>
<a name="1_Operationsonyears"></a>
<h1>Operations on years</h1><br>
<pre><span class="keyword">val</span> <a name="VALis_leap_year"></a>is_leap_year : <code class="type"><a href="Date.html#TYPEyear">year</a> -> bool</code></pre><div class="info">
Return <code class="code">true</code> if a year is a leap year; <code class="code">false</code> otherwise.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALsame_calendar"></a>same_calendar : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEyear">year</a> -> bool</code></pre><div class="info">
Return <code class="code">true</code> if two years have the same calendar; <code class="code">false</code> otherwise.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALdays_in_year"></a>days_in_year : <code class="type">?month:<a href="Date.html#TYPEmonth">month</a> -> <a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Number of days in a year.
<p>
<code class="code">days_in_year ~month y</code> returns the number of days in the year <code class="code">y</code> up to
the end of the given month. Thus <code class="code">days_in_year ~month:Dec y</code> is the same as
<code class="code">days_in_year y</code>.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALweeks_in_year"></a>weeks_in_year : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Number of weeks in a year.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALweek_first_last"></a>week_first_last : <code class="type">int -> <a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a> * <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Return the first and last days of a week in a year.<br>
<b>Since</b> 1.08<br>
</div>
<pre><span class="keyword">val</span> <a name="VALnth_weekday_of_month"></a>nth_weekday_of_month : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEmonth">month</a> -> <a href="Date.html#TYPEday">day</a> -> int -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
<code class="code">nth_weekday_of_month y m d n</code> returns the <code class="code">n</code>-th day <code class="code">d</code> in the month
<code class="code">m</code> of the year <code class="code">y</code> (for instance the 3rd Thursday of the month).<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALcentury"></a>century : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Century of a year.
E.g. <code class="code">century 2000</code> returns 20 and <code class="code">century 2001</code> returns 21.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALmillenium"></a>millenium : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Millenium of a year.
E.g. <code class="code">millenium 2000</code> returns 2 and <code class="code">millenium 2001</code> returns 3.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALsolar_number"></a>solar_number : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Solar number.
<p>
In the Julian calendar there is a one-to-one relationship between the
Solar number and the day on which a particular date falls.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALindiction"></a>indiction : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Indiction.
<p>
The Indiction was used in the middle ages to specify the position of a
year in a 15 year taxation cycle. It was introduced by emperor Constantine
the Great on 1 September 312 and ceased to be used in 1806.
<p>
The Indiction has no astronomical significance.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALgolden_number"></a>golden_number : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Golden number.
<p>
Considering that the relationship between the moon's phases and the days
of the year repeats itself every 19 years, it is natural to associate a
number between 1 and 19 with each year.
This number is the so-called Golden number.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALepact"></a>epact : <code class="type"><a href="Date.html#TYPEyear">year</a> -> int</code></pre><div class="info">
Epact.
<p>
The Epact is a measure of the age of the moon (i.e. the number of days
that have passed since an "official" new moon) on a particular date.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALeaster"></a>easter : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Easter Sunday.
<p>
In the Christian world, Easter (and the days immediately preceding it) is
the celebration of the death and resurrection of Jesus in (approximately)
AD 30.<br>
</div>
<pre><span class="keyword">val</span> <a name="VALcarnaval"></a>carnaval : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Carnaval Monday. <code class="code">carnaval y</code> is <code class="code">easter y - 48</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALmardi_gras"></a>mardi_gras : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Mardi Gras. <code class="code">mardi_gras y</code> is <code class="code">easter y - 47</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALash"></a>ash : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Ash Wednesday. <code class="code">ash y</code> is <code class="code">easter y - 46</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALpalm"></a>palm : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Palm Sunday. <code class="code">palm y</code> is <code class="code">easter y - 7</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALeaster_friday"></a>easter_friday : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Easter Friday. <code class="code">easter_friday y</code> is <code class="code">easter y - 2</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALeaster_saturday"></a>easter_saturday : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Easter Saturday. <code class="code">easter_saturday y</code> is <code class="code">easter y - 1</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALeaster_monday"></a>easter_monday : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Easter Monday. <code class="code">easter_monday y</code> is <code class="code">easter y + 1</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALascension"></a>ascension : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Ascension. <code class="code">ascension y</code> is <code class="code">easter y + 39</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALwithsunday"></a>withsunday : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Withsunday. <code class="code">withsunday y</code> is <code class="code">easter y + 49</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALwithmonday"></a>withmonday : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Withmonday. <code class="code">withmonday y</code> is <code class="code">easter y + 50</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
<pre><span class="keyword">val</span> <a name="VALcorpus_christi"></a>corpus_christi : <code class="type"><a href="Date.html#TYPEyear">year</a> -> <a href="Date.html#TYPEt">t</a></code></pre><div class="info">
Feast of Corpus Christi. <code class="code">corpus_christi y</code> is <code class="code">easter + 60</code>.<br>
<b>Since</b> 1.09.0<br>
</div>
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