How often will you change your car's screen wiper?

Somebody told me I should change it every two years. Is it ok?

Thanks
How often will you change your car's screen wiper?
I change it till it chatters and annoys the heck out of me or till it can no longer wipe the water off.



I like to keep a spare set in the trunk in case I'm on the road when it's time to replace them.
How often will you change your car's screen wiper?
whenever the blades don't wipe good and start leaving streaks, I usually replace mine about every 1.5 yrs.
I like to change mine at the first rain of the season. I have the kind of luck that if I did not change them they would go out at the worst possible moment.
There isn't really a specific interval. I change mine whenever they stop clearing the windshield efficiently. If your wipers are in good shape, and are still doing a good job, I see no point in spending money on new ones.