First day of the month at midnight

Why this pattern

Monthly reporting, billing cycles, archival sweeps, anything tied to a calendar month boundary. 0 0 1 * * reads as "minute 0, hour 0, day-of-month 1, every month, every weekday". The day-of-week field can be left as * because the day-of-month restriction is already specific enough.

Variations

• First of every quarter: 0 0 1 1,4,7,10 *
• 15th of the month: 0 0 15 * *
• Last day of the month (Quartz): 0 0 0 L * ?

Platform notes

Watch out for the year boundary: 0 0 1 1 * runs only once per year (January 1st). That is sometimes what you want, sometimes not. On Vercel Hobby, this single-fire-per-month schedule is well within the once-per-day limit.