I like to make timestamps, expressed in UTC, in following the format:

4-digit year, 2-digit month, 2-digit day, 2-digit hour, 2-digit minute, 2-digit seconds

Here are a few ways to do that easily.

Python 3.x

from time import gmtime, strftime
print(strftime("%Y%m%d%H%M%S", gmtime()))

PHP

echo gmdate("YmdHis");

*nix date command

date -u +%Y%m%d%H%M%S

Windows

Note that this is local time
for /f "tokens=2,3,4,5,6,7 delims=./: " %a in ('echo %DATE% %TIME%') do echo %a%b%c%d%e%f