The cron expression for every Monday at 09:00
0 9 * * 1
The day-of-week value 1 is Monday in standard Unix cron (Quartz uses 1=Sunday — see the dialect note in the every-week pillar). Equivalent name-alias form: 0 9 * * MON.
See the dedicated guide for the full breakdown: Cron every week.
Paste it into the editor above to see the next runs on a calendar.