Auto-reset bandwidth every 1st day of month if modified

When an account reaches its bandwidth limit, it will display the 509

bandwith limit exceeded page. I will then manually add a bandwidth by

going to WHM Home > Account Functions > Limit Bandwidth Usage and

increase the limit.

For example, the account original limit is set to only 5Gig, I will increase it to 10Gig.

On the first day of the next month, I want to auto reset the bandwidth

to its original limit to only 5gig (original value on the package).

Right now it does not do it. When I increase the limit to 10 Gig it does

not reset to 5Gig every first day of the month, I have to manually reset it by going to Limit Bandwidth Usage or Reset Account Bandwidth Limit page.