How often to change bowstring

[milcol]

Would like to know how often to change bow string I shoot on average about 30-35 per day alternating between my recurve and a longbow is there a recommended change.
                                                                          Thanks

[cbCrow]

What I do is wax my string about every 5-6 weeks and change about once a year. You always have spares that way.

[Mitch-In-NJ]

Assuming no visible signs that the string needs to be replaced, I also replace it once a year.

Same here.  I'll put a new one on a few weeks before hunting season.