When does L run in February?

On the 28th in a normal year and on the 29th in a leap year, because L always means the actual last day of that month.

Yes. "0 0 0 L-3 * *" is the third day before the end of the month.

example · 6 fields

Spring Cron Expression for Last day of month

Runs at 00:00:00 on the last calendar day of every month.

spring cron

0 0 0 L * *

@Scheduled(cron = "0 0 0 L * *")

Hardcoding "31" — that expression silently skips months with fewer days.
Forgetting February: "0 0 0 31 2 *" never runs, while L runs on the 28th (29th in a leap year).

When does L run in February?: On the 28th in a normal year and on the 29th in a leap year, because L always means the actual last day of that month.
Can I use L-<n>?: Yes. "0 0 0 L-3 * *" is the third day before the end of the month.