When using Xibo for Android, there is a built in Helper Command for changing the time zone without the need for a device restart to apply.
<ID> would be the database name for the time zone you wish to switch to.
This has been tested on Android 6 and 7 devices, as well as the DSCS9
In the event that the above command is not supported on the device, there is an alternative command that can be used on rooted devices.
Alternative command, for rooted devices only
The following command can be used for rooted devices only, but time zone changes will not be applied to any running apps (including the Xibo Player), until the device has been restarted.
Use the following command which includes a reboot, so will only need running once:
setprop persist.sys.timezone "<Timezone ID>"; reboot
setprop persist.sys.timezone "Europe/London"; reboot