progrium
Locale independence
Setting LC_ALL=C
See http://unix.stackexchange.com/questions/87745/what-does-lc-all-c-do
If you don't set LC_ALL=C for, say, sorting a list of numbers from a container/network source, it's going to be dependent on the system locale. That's a problem, if, say, that system's locale is designed for using commas as the decimal separator rather than dots.
Even if you're managing the environment in a container, make sure that the default locale in that container's environment is LC_ALL=C, rather than something like en_US.
Also, any time you record a date, you should do it as date -uIns, which saves it in human-readable ISO format with nanosecond precision and explicitly no timezone (date -Ins will record the local time with its offset to UTC, but any careful environment should be set for +0000 anyway). date %s is also useful, for recording the UTC Epoch time in seconds.
(If you only need to record the date to a lesser accuracy, you can use date -uIseconds, or date -Idate to just record the local date.)