spring replacement

At what intervals do you replace springs?  Talking about the main spring and recoil spring.

They last for thousands of rounds.

I replace the recoil spring when the brass starts landing more than 6 ft away.  For my idpa guns i just change them every year.  they are cheap

I didn't know that the springs need to be replaced!  1911 still seems to work ---pull trigger--bullet exits barrel--
new round chambers---  Same spring in use since I started shooting BE in 1955.  I still hit the target most of the time !!!  John

I agree with you John, if it ain't broke, don't fix it.

If it function's well no need to change, if you notice the brass flying out faster and further or more felt recoil then you might want to refresh your recoil spring with a new one, ive never had a mainspring wear out but I guess after many thousands of rounds it wouldn't hurt to change it.