OpenBSD’s timezone it set from the /etc/localtime binary file which will be soft linked (symbolic link) to one of the files located in the /usr/share/zoneinfo directory structure.
How to ,
1. Configuring the timezone is done using the /etc/localtime file.
2. Locate your timezone file in the /usr/share/zoneinfo/ directories.
3. Changing your timezone to Los Angeles (pacific) time
# rm /etc/localtime # ln -s /usr/share/zoneinfo/Asia/Singapore /etc/localtime