cron schedule expressions instead of minutes

[CruxCraft]

Not sure when it does the leader-boards exactly. If set to 720 minutes, does that mean it wont do the first one until 12 hours after the time I last started the server?; Meaning that it could possibly go days without a leader-board post if the server is restarted?

Would it be easy to switch from minutes to cron schedule expressions?

0 6,18 * * * https://crontab.guru/#0_6,18___*

This way we could have the leader-boards post at specific times even if the servers restart... It wouldn't be limited to an interval either then; Could easily do 08:30 and 17:15 using cron schedule expressions (I would just include a link to https://crontab.guru for those unfamiliar)

EDIT: with this I could even set it up so it only does it on Wednesdays and Sundays at noon which would be amazing 0 12 * * 3,7