Big-Data-HPC-Platform/docs/SLR-Mods/DateDataTypes.xml

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<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<sect1 id="Date_Data_Types">
  <title><emphasis role="bold">Date Data Types</emphasis></title>

  <para><emphasis role="bold">STD.Date.Date_rec<indexterm>
      <primary>STD.Date.Date_rec</primary>
    </indexterm><indexterm>
      <primary>Date.Date_rec</primary>
    </indexterm></emphasis></para>

  <para><emphasis role="bold">STD.Date.Date_t<indexterm>
      <primary>STD.Date.Date_t</primary>
    </indexterm><indexterm>
      <primary>Date.Date_t</primary>
    </indexterm></emphasis></para>

  <para><emphasis role="bold">STD.Date.Days_t<indexterm>
      <primary>STD.Date.Days_t</primary>
    </indexterm><indexterm>
      <primary>Date.Days_t</primary>
    </indexterm></emphasis></para>

  <informaltable colsep="0" frame="none" rowsep="0">
    <tgroup cols="2">
      <colspec colwidth="80.50pt" />

      <colspec />

      <tbody>
        <row>
          <entry><emphasis role="bold">Date_rec</emphasis></entry>

          <entry>A RECORD structure containing three fields, and INTEGER2
          year, an UNSIGNED1 month, and an UNSIGNED1 day.</entry>
        </row>

        <row>
          <entry><emphasis role="bold">Date_t</emphasis></entry>

          <entry>An UNSIGNED4 containing a date value in YYYYMMDD
          format.</entry>
        </row>

        <row>
          <entry><emphasis role="bold">Days_t</emphasis></entry>

          <entry>An UNSIGNED4 containing a date value representing the number
          of elapsed days since a particular base date. This number can be the
          number of days in the common era (January 1, 1AD = 1) based on
          either the Julian or Gregorian calendars, or the number of elapsed
          days since the Gregorian calendar's January 1, 1900 (January 1, 1900
          = 1).</entry>
        </row>
      </tbody>
    </tgroup>
  </informaltable>

  <para>The three Date data types defined in the Date Standard Library
  are:</para>

  <programlisting format="linespecific">    // A record stucture with the different elements separated out.
EXPORT Date_rec := RECORD
  INTEGER2   year;
  UNSIGNED1  month;
  UNSIGNED1  day;
END;

    //An unsigned number holding a date in the decimal form YYYYMMDD.  
    //This type does not support dates prior to 1AD
EXPORT Date_t := UNSIGNED4;

    //A number of elapsed days.  Value depends on the function called.
EXPORT Days_t := UNSIGNED4;
</programlisting>
</sect1>