%SubTimesLocal function


Function
The function deducts absolute time TimeB from absolute time TimeA. A result is value of Relative time type.

Declaration


REAL %SubTimesLocal(
   TIME in TimeA,
   TIME in TimeB,
   TEXT in timeZone := %GetCurrentTimeZone()
 )
Parameters


TimeAAbsolute time.
TimeBAbsolute time.
timeZoneName of the time zone used for conversion to local time (e.g. "Europe/London") or definition of fixed offset from UTC using format "(+|-)hh[:mi[:ss]]", where hh defines number of hours, mi defines number of minutes, and ss defines number of seconds. Sign as well as number of hours are mandatory parts of offset definition, number of minutes and seconds are optional and default to 0 (e.g. "+02:30" defines offset of 2 hours and 30 minutes from UTC). Empty text has the same meaning as function %GetCurrentTimeZone.
Note: For historical reasons, integer parameter is also accepted. Its interpretation is as follows: 0 - zone "Europe/London", 3600 - zone "Europe/Bratislava", 7200 - zone "Europe/Kiev", 21600 - zone "Asia/Almaty". Usage of integer parameter is deprecated and generates warning into log file!
Description
The function %SubTimesLocal deducts one absolute time from other one. The result will not be influenced by the fact if the time offset was or was not in this interval. For example, the difference between 4:00 and 1:00 a.m. is always three hours.
Example


; =================================================================
;  Using time zone "Europe/Bratislava"
;  Daylight saving time was observed in year 2009, therefore time shifts occured.
;  Winter [B] time was 1 hour ahead of UTC, summer [A] time was 2 hours ahead of UTC.
;  Summer time was from 29th March 2009 to 24th October 2009.
;  A3:00:00 is changed to B2:00:00 on Sunday (25th October 2009).
; =================================================================
 
BEGIN
  TIME _timeA
  TIME _timeB
  TIME _baseTime

  REAL _subLocal1
  REAL _subLocal2

  ; 2009-10-25 00:30:00 UTC
  _timeA := %StrToTimeEx("2009-10-25 A2:30:00", "yyyy-mm-dd hh:mi:ss", "Europe/Bratislava")
  ; 2009-10-25 01:30:00 UTC
  _timeB := %StrToTimeEx("2009-10-25 B2:30:00", "yyyy-mm-dd hh:mi:ss", "Europe/Bratislava")
  ; 2009-10-24 23:30:00 UTC
  _baseTime := %StrToTimeEx("2009-10-25 01:30:00", "yyyy-mm-dd hh:mi:ss", "Europe/Bratislava")
 
  ; difference 1 hour(s) (3600 seconds)
  _subLocal1 := %SubTimesLocal(_timeA, _baseTime, "Europe/Bratislava")
  ; difference 1 hour(s) (3600 seconds)
  _subLocal2 := %SubTimesLocal(_timeB, _baseTime, "Europe/Bratislava")
 
 END