@Jim-Brown I too am pretty familiar with Linux over a similar time period. However, I still keep getting thrown by the OpenWrt differences since it is in general a very much cut down version of Linux.
However, I can usually find what i want to know somewhere on the OpenWrt sites. The following are good starting points:
And in particular in relation to your questions about timezones, see information in:https://wiki.openwrt.org/doc/uci/system