Despite the system time as well as the timezone are correct, Horde for some reason uses the different timezone (UTC by default).How can the timezone be configured for Horde server-wide?
Horde uses its own 'php.ini' file and the timezone is not configured there.
Add the timezone parameter in
date.timezone = Asia/Singapore
Get full list of TimeZones you can find by the follwoing link:
NOTE: Each user can configure its own timezone.