=head2 Time ranges
Last four weeks: --start end-4w --end 00:00
- January 2001: --start 200101010000 --end start+31d
- January 2001: --start 200101010000 --end 200102010000
+ January 2001: --start 20010101 --end start+31d
+ January 2001: --start 20010101 --end 20010201
Last hour: --start end-1h
Last 24 hours: <nothing at all>
Yesterday: --end 00:00