PSA: TIMEZONE environment variable now required for release 118

[lamarios]

The TIMEZONE environment variable is now required.
I am switching the expense time to timestamps instead of string date that were becoming less and less convenient.

[tsuihak]

Add the TIMEZONE variable to the docker compose example in the SSS service in the readme. This variable is in the postgres-sss service. Without this, docker would not start. Please fix readme do docker compose. I had done the test on version 124 and 125. I didn't do the test on version 127. Sorry for the English.