Time Zone and Conversion

Temporal objects in DolphinDB do not include time zone information. It is up to users to interpret the time zones of the temporal objects.

DolphinDB automatically detects the local time zones.

We can use the following functions to convert time between different time zones:

(1) localtime convert time from GMT (Greenwich Mean Time) to local time zone.

(2) gmtime convert time from local time zone to GMT (Greenwich Mean Time).

(3) convertTZ convert time between different time zones.

Time zone conversion functions address the daylight saving time automatically if either the source time zone or the destination time zone adopts the daylight saving time.

localtime(2018.01.22T15:20:26);
// output
2018.01.22T10:20:26

localtime(2017.12.16T18:30:10.001);
// output
2017.12.16T13:30:10.001

gmtime(2018.01.22 10:20:26);
// output
2018.01.22T15:20:26

gmtime(2017.12.16T13:30:10.008);
// output
2017.12.16T18:30:10.008

convertTZ(2016.04.25T08:25:45,"US/Eastern","Asia/Shanghai");
// output
2016.04.25T20:25:45


// with daylight saving time in US:
convertTZ(2016.04.25T19:25:45,"US/Eastern","Asia/Shanghai");
// output
2016.04.26T07:25:45