Switching Time Zones¶
Switching an existing ZonedDateTime from one TimeZone to another can be done with the function astimezone:
julia> zdt = ZonedDateTime(2014, 1, 1, tz"UTC")
2014-01-01T00:00:00+00:00
julia> astimezone(zdt, tz"Asia/Tokyo")
2014-01-01T09:00:00+09:00
Parsing strings¶
ZonedDateTime parsing extends the functionality provided by Dates. If you haven't already it is recommended that you first read the official Julia manual on Date and DateTime. The TimeZones package adds z and Z to the list of available parsing character codes:
| Code | Matches | Comment |
|---|---|---|
z |
+04:00, +0400, UTC+4 | Matches a numeric UTC offset |
Z |
Asia/Dubai, UTC | Matches names of time zones from the TZ database |
Note that with the exception of "UTC" and "GMT" time zone abbrevations cannot be parsed using the Z character code since most abbreviations are ambiguous. For example abbreviation "MST" could be interpreted as "Mountain Standard Time" (UTC-7) or "Moscow Summer Time" (UTC+3:31).
Parsing a ZonedDateTime just requires the text to parse and a format string:
julia> ZonedDateTime("20150101-0700", "yyyymmddzzzz")
2015-01-01T00:00:00-07:00
julia> ZonedDateTime("2015-08-06T22:25:31+07:00", "yyyy-mm-ddTHH:MM:SSzzzz")
2015-08-06T22:25:31+07:00
When parsing several ZonedDateTime strings which use the same format you will see better performance if you first create a Dates.DateFormat instead of passing in a raw format string.
julia> df = Dates.DateFormat("yy-mm-ddz");
julia> ZonedDateTime("2015-03-29+01:00", df)
2015-03-29T00:00:00+01:00
julia> ZonedDateTime("2015-03-30+02:00", df)
2015-03-30T00:00:00+02:00
Formatting strings¶
Formatting a ZonedDateTime as a string also extends the functionality provided by Base.Dates. The TimeZones package adds the new formatting character codes z and Z to the list of available formatting character codes:
| Code | Examples | Comment |
|---|---|---|
z |
+04:00 | Numeric UTC offset |
Z |
GST, UTC | Time zone abbreviation |
It is recommended that you prefer the use of the z character code over Z time zone abbreviations can be interpreted in different ways.
Formatting uses the Dates.format function with a ZonedDateTime and a format string:
julia> zdt = ZonedDateTime(2015,8,6,22,25,tz"Europe/Warsaw")
2015-08-06T22:25:00+02:00
julia> Dates.format(zdt, "yyyymmddzzzz")
"20150806+02:00"
julia> Dates.format(zdt, "yyyy-mm-dd HH:MM ZZZ")
"2015-08-06 22:25 CEST"