Dear Tim:
How often should a cellist change strings if they play only about three days a week? In talking to my cellist friends, there are many views on this.
This is a tough question. Musicians change their strings with varying frequencies. Some change them at least once a month. And some don't do it for a few years. I definitely wouldn't recommend the latter.
It depends on how you play. If you thrash the cello, you will wear them out sooner than if you are more delicate. Strings start to sound dead and have a hard time keeping their pitch after awhile. When this happens, it's time to change them.
You might try changing them after 3-4 months and see if there is a noticable difference.
Tim Janof