Quick Question abotu backups

[pryj]

I have 24 hour cron jobs:

1. make backup
2. Make second backup (30 minutes after 1st one)
3. Gzip first backup (5 minutes after 2nd step)
4. Gzip second one (20 minutes after 3rd step)

Now, problem is, it's not overwriting the gzipped stuff. It overwrties the sql files but it wont overwrite the gzipped ones.

How do I make it overwrite?