ObjectPascal DateTimeToString Procedure Rich formatting of a TDateTime variable into a string SysUtils unit

1  procedure DateTimeToString ( var Result : string; const Formatting : string; DateTime : TDateTime ) ; 2  procedure DateTimeToString ( var Result : string; const Formatting : string; DateTime : TDateTime; const FormatSettings : TFormatSettings ) ;

Description The DateTimeToString procedure provides rich formatting of a TDateTime value DateTime into a string Result. Formatting is defined by the Formatting string.   The Formatting string can comprise a mix of ordinary characters (that are passed unchanged to the result string), and data formatting characters. This formatting is best explained by the example code.   The following (non-Asian) formatting character strings can be used in the Formatting string:   y  = Year last 2 digits yy  = Year last 2 digits yyyy  = Year as 4 digits m  = Month number no-leading 0 mm  = Month number as 2 digits mmm  = Month using ShortDayNames (Jan) mmmm  = Month using LongDayNames (January) d  = Day number no-leading 0 dd  = Day number as 2 digits ddd  = Day using ShortDayNames (Sun) dddd  = Day using LongDayNames  (Sunday) ddddd  = Day in ShortDateFormat dddddd  = Day in LongDateFormat   c  = Use ShortDateFormat + LongTimeFormat h  = Hour number no-leading 0 hh  = Hour number as 2 digits n  = Minute number no-leading 0 nn  = Minute number as 2 digits s  = Second number no-leading 0 ss  = Second number as 2 digits z  = Milli-sec number no-leading 0s zzz  = Milli-sec number as 3 digits t  = Use ShortTimeFormat tt  = Use LongTimeFormat   am/pm  = Use after h : gives 12 hours + am/pm a/p  = Use after h : gives 12 hours + a/p ampm  = As a/p but TimeAMString,TimePMString /  = Substituted by DateSeparator value :  = Substituted by TimeSeparator value   In addition to this formatting, various of the above options are affected by the following variables, withe their default values :   DateSeparator  = / TimeSeparator  = : ShortDateFormat  = dd/mm/yyyy LongDateFormat  = dd mmm yyyy TimeAMString  = AM TimePMString  = PM ShortTimeFormat  = hh:mm LongTimeFormat  = hh:mm:ss ShortMonthNames  = Jan Feb ... LongMonthNames  = January, February ... ShortDayNames  = Sun, Mon ... LongDayNames  = Sunday, Monday ... TwoDigitCenturyWindow  = 50   Version 2 of this function is for use within threads. You furnish the FormatSettings record before invoking the call. It takes a local copy of global formatting variables that make the routine thread safe. Related commands DateSeparator The character used to separate display date fields DateTimeToStr Converts TDateTime date and time values to a string LongDateFormat Long version of the date to string format LongDayNames An array of days of the week names, starting 1 = Sunday LongMonthNames An array of days of the month names, starting 1 = January LongTimeFormat Long version of the time to string format ShortDateFormat Compact version of the date to string format ShortDayNames An array of days of the week names, starting 1 = Sunday ShortMonthNames An array of days of the month names, starting 1 = Jan ShortTimeFormat Short version of the time to string format StrToDateTime Converts a date+time string into a TDateTime value TimeAMString Determines AM value in DateTimeToString procedure TimePMString Determines PM value in DateTimeToString procedure TimeSeparator The character used to separate display time fields TwoDigitYearCenturyWindow Sets the century threshold for 2 digit year string conversions		Example code : Showing all of the date field formatting data types var   myDate : TDateTime;   formattedDateTime : string; begin   // Set up our TDateTime variable with a full date and time :   // 5th of June 2000 at 01:02:03.004  (.004 milli-seconds)   myDate := EncodeDateTime(2000, 6, 5, 1, 2, 3, 4);   // Date only - numeric values with no leading zeroes (except year)   DateTimeToString(formattedDateTime, 'd/m/y', myDate);   WriteLn('              d/m/y = '+formattedDateTime);   // Date only - numeric values with leading zeroes   DateTimeToString(formattedDateTime, 'dd/mm/yy', myDate);   WriteLn('           dd/mm/yy = '+formattedDateTime);   // Use short names for the day, month, and add freeform text ('of')   DateTimeToString(formattedDateTime, 'ddd d of mmm yyyy', myDate);   WriteLn('  ddd d of mmm yyyy = '+formattedDateTime);   // Use long names for the day and month   DateTimeToString(formattedDateTime, 'dddd d of mmmm yyyy', myDate);   WriteLn('dddd d of mmmm yyyy = '+formattedDateTime);   // Use the ShortDateFormat settings only   DateTimeToString(formattedDateTime, 'ddddd', myDate);   WriteLn('              ddddd = '+formattedDateTime);   // Use the LongDateFormat settings only   DateTimeToString(formattedDateTime, 'dddddd', myDate);   WriteLn('             dddddd = '+formattedDateTime);   // Use the ShortDateFormat + LongTimeFormat settings   DateTimeToString(formattedDateTime, 'c', myDate);   WriteLn('                  c = '+formattedDateTime); end; Show full unit code                  d/m/y = 5/6/00               dd/mm/yy = 05/06/00      ddd d of mmm yyyy = Mon 5 of Jun 2000    dddd d of mmmm yyyy = Monday 5 of June 2000                  ddddd = 05/06/2000                 dddddd = 05 June 2000                      c = 05/06/2000 01:02:03   Example code : Showing all of the time field formatting data types var   myDate : TDateTime;   formattedDateTime : string; begin   // Set up our TDateTime variable with a full date and time :   // 5th of June 2000 at 01:02:03.004  (.004 milli-seconds)   myDate := EncodeDateTime(2000, 6, 5, 1, 2, 3, 4);   // Time only - numeric values with no leading zeroes   DateTimeToString(formattedDateTime, 'h:n:s.z', myDate);   WriteLn('     h:n:s.z = '+formattedDateTime);   // Time only - numeric values with leading zeroes   DateTimeToString(formattedDateTime, 'hh:nn:ss.zzz', myDate);   WriteLn('hh:nn:ss.zzz = '+formattedDateTime);   // Use the ShortTimeFormat settings only   DateTimeToString(formattedDateTime, 't', myDate);   WriteLn('           t = '+formattedDateTime);   // Use the LongTimeFormat settings only   DateTimeToString(formattedDateTime, 'tt', myDate);   WriteLn('          tt = '+formattedDateTime);   // Use the ShortDateFormat + LongTimeFormat settings   DateTimeToString(formattedDateTime, 'c', myDate);   WriteLn('           c = '+formattedDateTime); end; Show full unit code         h:m:s.z = 1:2:3.4    hh:mm:ss.zzz = 01:02:03.004               t = 01:02              tt = 01:02:03               c = 05/06/2000 01:02:03   Example code : Showing the effect of local date format settings var   myDate : TDateTime;   formattedDateTime : string; begin   // Set up our TDateTime variable with a full date and time :   // 5th of June 2049 at 01:02:03.004  (.004 milli-seconds)   //   // Note that 49 is treated as 2049 as follows :   //               TwoDigitYearCenturyWindow => 50   //                            Current year => 2008 (at time of writing)   //      Subtract TwoDigitYearCenturyWindow => 1958   //            2 digit year to be converted => 49   //  Compare with the last 2 digits of 1958 => Less   //      So the year is in the next century => 2049   // (58 would be converted to 1958)   myDate := StrToDateTime('05/06/49 01:02:03.004');   // Demonstrate default locale settings   // Use the DateSeparator and TimeSeparator values   DateTimeToString(formattedDateTime, 'dd/mm/yy hh:nn:ss', myDate);   WriteLn('dd/mm/yy hh:nn:ss = '+formattedDateTime);   // Use ShortMonthNames   DateTimeToString(formattedDateTime, 'mmm', myDate);   WriteLn('              mmm = '+formattedDateTime);   // Use LongMonthNames   DateTimeToString(formattedDateTime, 'mmmm', myDate);   WriteLn('             mmmm = '+formattedDateTime);   // Use ShortDayNames   DateTimeToString(formattedDateTime, 'ddd', myDate);   WriteLn('              ddd = '+formattedDateTime);   // Use LongDayNames   DateTimeToString(formattedDateTime, 'dddd', myDate);   WriteLn('             dddd = '+formattedDateTime);   // Use the ShortDateFormat string   DateTimeToString(formattedDateTime, 'ddddd', myDate);   WriteLn('            ddddd = '+formattedDateTime);   // Use the LongDateFormat string   DateTimeToString(formattedDateTime, 'dddddd', myDate);   WriteLn('           dddddd = '+formattedDateTime);   // Use the TimeAmString   DateTimeToString(formattedDateTime, 'hhampm', myDate);   WriteLn('           hhampm = '+formattedDateTime);   // Use the ShortTimeFormat string   DateTimeToString(formattedDateTime, 't', myDate);   WriteLn('                t = '+formattedDateTime);   // Use the LongTimeFormat string   DateTimeToString(formattedDateTime, 'tt', myDate);   WriteLn('               tt = '+formattedDateTime);   // Use the TwoDigitCenturyWindow   DateTimeToString(formattedDateTime, 'dd/mm/yyyy', myDate);   WriteLn('       dd/mm/yyyy = '+formattedDateTime);   WriteLn('');   // Now change the defaults   DateSeparator      := '-';   TimeSeparator      := '_';   ShortDateFormat    := 'dd/mmm/yy';   LongDateFormat     := 'dddd dd of mmmm of yyyy';   TimeAMString       := 'morning';   TimePMString       := 'afternoon';   ShortTimeFormat    := 'hh:nn:ss';   LongTimeFormat     := 'hh : nn : ss . zzz';   ShortMonthNames[6] := 'JUN';   LongMonthNames[6]  := 'JUNE';   ShortDayNames[1]   := 'SUN';   LongDayNames[1]    := 'SUNDAY';   TwoDigitYearCenturyWindow := 75; // This means 49 is treated as 1949   // Set up our TDateTime variable with the same value as before   // except that we must use the new date and time separators   // The TwoDigitYearCenturyWindow variable only takes effect here   myDate := StrToDateTime('05-06-49 01_02_03.004');   // Use the DateSeparator and TimeSeparator values   DateTimeToString(formattedDateTime, 'dd/mm/yy hh:nn:ss', myDate);   WriteLn('dd/mm/yy hh:nn:ss = '+formattedDateTime);   // Use ShortMonthNames   DateTimeToString(formattedDateTime, 'mmm', myDate);   WriteLn('              mmm = '+formattedDateTime);   // Use LongMonthNames   DateTimeToString(formattedDateTime, 'mmmm', myDate);   WriteLn('             mmmm = '+formattedDateTime);   // Use ShortDayNames   DateTimeToString(formattedDateTime, 'ddd', myDate);   WriteLn('              ddd = '+formattedDateTime);   // Use LongDayNames   DateTimeToString(formattedDateTime, 'dddd', myDate);   WriteLn('             dddd = '+formattedDateTime);   // Use the ShortDateFormat string   DateTimeToString(formattedDateTime, 'ddddd', myDate);   WriteLn('            ddddd = '+formattedDateTime);   // Use the LongDateFormat string   DateTimeToString(formattedDateTime, 'dddddd', myDate);   WriteLn('           dddddd = '+formattedDateTime);   // Use the TimeAmString   DateTimeToString(formattedDateTime, 'hhampm', myDate);   WriteLn('           hhampm = '+formattedDateTime);   // Use the ShortTimeFormat string   DateTimeToString(formattedDateTime, 't', myDate);   WriteLn('                t = '+formattedDateTime);   // Use the LongTimeFormat string   DateTimeToString(formattedDateTime, 'tt', myDate);   WriteLn('               tt = '+formattedDateTime);   // Use the TwoDigitCenturyWindow   DateTimeToString(formattedDateTime, 'dd/mm/yyyy', myDate);   WriteLn('       dd/mm/yyyy = '+formattedDateTime); end; Show full unit code    dd/mm/yy hh:mm:ss = 05/06/49 01:02:03                  mmm = Jun                 mmmm = June                  ddd = Sat                 dddd = Saturday                ddddd = 05/06/2049               dddddd = 05 June 2049               hhampm = 01AM                    t = 01:02                   tt = 01:02:03           dd/mm/yyyy = 05/06/2049       dd/mm/yy hh:nn:ss = 05-06-49 01_02_03                  mmm = JUN                 mmmm = JUNE                  ddd = SUN                 dddd = SUNDAY                ddddd = 05-JUN-49               dddddd = SUNDAY 05 of JUNE of 1949               hhampm = 01morning                    t = 01_02_03                   tt = 01 _ 02 _ 03 . 004           dd/mm/yyyy = 05-06-1949