With systemd if I'm not mistaken this is just: OnCalendar=Mon *-*-* 12:00:00 Here's the list of examples from man systemd.time: The following spec

With systemd if I'm not mistaken this is just: OnCalendar=Mon *-*-* 12:00:00 Here's the list of examples from man systemd.time: The following special expressions may be used as shorthands for longer normalized forms: minutely → *-*-* *:*:00 hourly → *-*-* *:00:00 daily → *-*-* 00:00:00 monthly → *-*-01 00:00:00 weekly → Mon *-*-* 00:00:00 yearly → *-01-01 00:00:00 quarterly → *-01,04,07,10-01 00:00:00 semiannually → *-01,07-01 00:00:00 Examples for valid timestamps and their normalized form: Sat,Thu,Mon..Wed,Sat..Sun → Mon..Thu,Sat,Sun *-*-* 00:00:00 Mon,Sun 12-*-* 2,1:23 → Mon,Sun 2012-*-* 01,02:23:00 Wed *-1 → Wed *-*-01 00:00:00 Wed..Wed,Wed *-1 → Wed *-*-01 00:00:00 Wed, 17:48 → Wed *-*-* 17:48:00 Wed..Sat,Tue 12-10-15 1:2:3 → Tue..Sat 2012-10-15 01:02:03 *-*-7 0:0:0 → *-*-07 00:00:00 10-15 → *-10-15 00:00:00 monday *-12-* 17:00 → Mon *-12-* 17:00:00 Mon,Fri *-*-3,1,2 *:30:45 → Mon,Fri *-*-01,02,03 *:30:45 12,14,13,12:20,10,30 → *-*-* 12,13,14:10,20,30:00 12..14:10,20,30 → *-*-* 12..14:10,20,30:00 mon,fri *-1/2-1,3 *:30:45 → Mon,Fri *-01/2-01,03 *:30:45 03-05 08:05:40 → *-03-05 08:05:40 08:05:40 → *-*-* 08:05:40 05:40 → *-*-* 05:40:00 Sat,Sun 12-05 08:05:40 → Sat,Sun *-12-05 08:05:40 Sat,Sun 08:05:40 → Sat,Sun *-*-* 08:05:40 2003-03-05 05:40 → 2003-03-05 05:40:00 05:40:23.4200004/3.1700005 → *-*-* 05:40:23.420000/3.170001 2003-02..04-05 → 2003-02..04-05 00:00:00 2003-03-05 05:40 UTC → 2003-03-05 05:40:00 UTC 2003-03-05 → 2003-03-05 00:00:00 03-05 → *-03-05 00:00:00 hourly → *-*-* *:00:00 daily → *-*-* 00:00:00 daily UTC → *-*-* 00:00:00 UTC monthly → *-*-01 00:00:00 weekly → Mon *-*-* 00:00:00 weekly Pacific/Auckland → Mon *-*-* 00:00:00 Pacific/Auckland yearly → *-01-01 00:00:00 annually → *-01-01 00:00:00 *:2/3 → *-*-* *:02/3:00