Document wxDateTime::GregorianAdoption enum and TimeZone class.

These types are referenced by the other documented functions so should be
documented themselves.

Closes #13959.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70571 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/datetime.h

@@ -170,6 +170,128 @@ public:
         Julian      ///< calendar in use since -45 until the 1582 (or later)
     };
 
+    /**
+        Values corresponding to different dates of adoption of the Gregorian
+        calendar.
+
+        @see IsGregorianDate
+     */
+    enum GregorianAdoption
+    {
+        Gr_Unknown,    ///< no data for this country or it's too uncertain to use
+        Gr_Standard,   ///< on the day 0 of Gregorian calendar: 15 Oct 1582
+
+        Gr_Alaska,             ///< Oct 1867 when Alaska became part of the USA
+        Gr_Albania,            ///< Dec 1912
+
+        Gr_Austria = Gr_Unknown,    ///< Different regions on different dates
+        Gr_Austria_Brixen,          ///< 5 Oct 1583 -> 16 Oct 1583
+        Gr_Austria_Salzburg = Gr_Austria_Brixen,
+        Gr_Austria_Tyrol = Gr_Austria_Brixen,
+        Gr_Austria_Carinthia,       ///< 14 Dec 1583 -> 25 Dec 1583
+        Gr_Austria_Styria = Gr_Austria_Carinthia,
+
+        Gr_Belgium,            ///< Then part of the Netherlands
+
+        Gr_Bulgaria = Gr_Unknown, ///< Unknown precisely (from 1915 to 1920)
+        Gr_Bulgaria_1,         ///<      18 Mar 1916 -> 1 Apr 1916
+        Gr_Bulgaria_2,         ///<      31 Mar 1916 -> 14 Apr 1916
+        Gr_Bulgaria_3,         ///<      3 Sep 1920 -> 17 Sep 1920
+
+        Gr_Canada = Gr_Unknown,   ///< Different regions followed the changes in
+                               ///< Great Britain or France
+
+        Gr_China = Gr_Unknown,    ///< Different authorities say:
+        Gr_China_1,            ///<      18 Dec 1911 -> 1 Jan 1912
+        Gr_China_2,            ///<      18 Dec 1928 -> 1 Jan 1929
+
+        Gr_Czechoslovakia,     ///< (Bohemia and Moravia) 6 Jan 1584 -> 17 Jan 1584
+        Gr_Denmark,            ///< (including Norway) 18 Feb 1700 -> 1 Mar 1700
+        Gr_Egypt,              ///< 1875
+        Gr_Estonia,            ///< 1918
+        Gr_Finland,            ///< Then part of Sweden
+
+        Gr_France,             ///< 9 Dec 1582 -> 20 Dec 1582
+        Gr_France_Alsace,      ///<      4 Feb 1682 -> 16 Feb 1682
+        Gr_France_Lorraine,    ///<      16 Feb 1760 -> 28 Feb 1760
+        Gr_France_Strasbourg,  ///< February 1682
+
+        Gr_Germany = Gr_Unknown,  ///< Different states on different dates:
+        Gr_Germany_Catholic,   ///<      1583-1585 (we take 1584)
+        Gr_Germany_Prussia,    ///<      22 Aug 1610 -> 2 Sep 1610
+        Gr_Germany_Protestant, ///<      18 Feb 1700 -> 1 Mar 1700
+
+        Gr_GreatBritain,       ///< 2 Sep 1752 -> 14 Sep 1752 (use 'cal(1)')
+
+        Gr_Greece,             ///< 9 Mar 1924 -> 23 Mar 1924
+        Gr_Hungary,            ///< 21 Oct 1587 -> 1 Nov 1587
+        Gr_Ireland = Gr_GreatBritain,
+        Gr_Italy = Gr_Standard,
+
+        Gr_Japan = Gr_Unknown,    ///< Different authorities say:
+        Gr_Japan_1,            ///<      19 Dec 1872 -> 1 Jan 1873
+        Gr_Japan_2,            ///<      19 Dec 1892 -> 1 Jan 1893
+        Gr_Japan_3,            ///<      18 Dec 1918 -> 1 Jan 1919
+
+        Gr_Latvia,             ///< 1915-1918 (we take 1915)
+        Gr_Lithuania,          ///< 1915
+        Gr_Luxemburg,          ///< 14 Dec 1582 -> 25 Dec 1582
+        Gr_Netherlands = Gr_Belgium, ///< (including Belgium) 1 Jan 1583
+
+        /**
+            Special case of Groningen.
+
+            The Gregorian calendar was introduced twice in Groningen, first
+            time 28 Feb 1583 was followed by 11 Mar 1583, then it has gone back
+            to Julian in the summer of 1584 and then 13 Dec 1700 was followed
+            by 12 Jan 1701 -- which is the date we take into account here.
+         */
+        Gr_Netherlands_Groningen,  ///< 13 Dec 1700 -> 12 Jan 1701
+        Gr_Netherlands_Gelderland, ///< 30 Jun 1700 -> 12 Jul 1700
+        Gr_Netherlands_Utrecht,    ///< (and Overijssel) 30 Nov 1700->12 Dec 1700
+        Gr_Netherlands_Friesland,  ///< (and Drenthe) 31 Dec 1700 -> 12 Jan 1701
+
+        Gr_Norway = Gr_Denmark,       ///< Then part of Denmark
+        Gr_Poland = Gr_Standard,
+        Gr_Portugal = Gr_Standard,
+        Gr_Romania,                ///< 31 Mar 1919 -> 14 Apr 1919
+        Gr_Russia,                 ///< 31 Jan 1918 -> 14 Feb 1918
+        Gr_Scotland = Gr_GreatBritain,
+        Gr_Spain = Gr_Standard,
+
+        /**
+            Special case of Sweden.
+
+            Sweden has a curious history. Sweden decided to make a gradual
+            change from the Julian to the Gregorian calendar. By dropping every
+            leap year from 1700 through 1740 the eleven superfluous days would
+            be omitted and from 1 Mar 1740 they would be in sync with the
+            Gregorian calendar. (But in the meantime they would be in sync with
+            nobody!)
+
+            So 1700 (which should have been a leap year in the Julian calendar)
+            was not a leap year in Sweden. However, by mistake 1704 and 1708
+            became leap years. This left Sweden out of synchronisation with
+            both the Julian and the Gregorian world, so they decided to go back
+            to the Julian calendar. In order to do this, they inserted an extra
+            day in 1712, making that year a double leap year! So in 1712,
+            February had 30 days in Sweden.
+
+            Later, in 1753, Sweden changed to the Gregorian calendar by
+            dropping 11 days like everyone else and this is what we use here.
+         */
+        Gr_Sweden = Gr_Finland,       ///< 17 Feb 1753 -> 1 Mar 1753
+
+        Gr_Switzerland = Gr_Unknown,///< Different cantons used different dates
+        Gr_Switzerland_Catholic,    ///<      1583, 1584 or 1597 (we take 1584)
+        Gr_Switzerland_Protestant,  ///<      31 Dec 1700 -> 12 Jan 1701
+
+        Gr_Turkey,                 ///< 1 Jan 1927
+        Gr_USA = Gr_GreatBritain,
+        Gr_Wales = Gr_GreatBritain,
+        Gr_Yugoslavia              ///< 1919
+    };
+
     /**
         Date calculations often depend on the country and wxDateTime allows to set
         the country whose conventions should be used using SetCountry(). It takes
@@ -244,6 +366,27 @@ public:
     };
 
 
+    /**
+        Class representing a time zone.
+
+        The representation is simply the offset, in seconds, from UTC.
+     */
+    class WXDLLIMPEXP_BASE TimeZone
+    {
+    public:
+        /// Constructor for a named time zone.
+        TimeZone(TZ tz);
+
+        /// Constructor for the given offset in seconds.
+        TimeZone(long offset = 0);
+
+        /// Create a time zone with the given offset in seconds.
+        static TimeZone Make(long offset);
+
+        /// Return the offset of this time zone from UTC, in seconds.
+        long GetOffset() const;
+    };
+
     /**
         Contains broken down date-time representation.