I don't think there is a specific time, just whenever you feel the need. If it starts to sound shitty or if one breaks that's pretty much when I change them. There are some people that don't change strings for monthes and monthes and some don't change for years even.

It all depends on how often and agressively you play but as a general guideline you should change them out three or four times a year.

It depends on how you play, what type of guitar, and even what type of strings you buy. I hear that they make strings that are supposed to keep their tone for over a year

you know you can tune them and not change them

They should get changed when they break which is based upon your frequency of playing the guitar.

It depends........... How often you play. If the strings become untuneable. If you play professionally, always carry an extra full set of strings as a backup. Strings can break at the most unopportune time. Practice changing a broken string at home, so you can make the change on stage, much faster.

Wrong wrong wrong wrong wrong...sorry. In all honesty that is a question that can only be answered by the individual player. For instance Clapton never changes his strings until they break, or he used to do that. Different strings need different attention. Nylon classical guitar strings have different lifetimes and wear differently then electric guitar strings and acoustic guitar strings. Some people like the sound of brand new strings, they sound brighter. Some like old strings because they are dead sounding and more percussive, less bright. There are coated strings that hardly need replacing called Elixirs. I would say it also depends on the area you live. If it's near the ocean the strings will probably go bad faster because of the salt air and humidity. So there are so many factors and personal choices. I change mine when I see the frets leaving wear spots. There is a time just when the string goes a little dead that I like the way they feel and sound, then it goes passed playability for me after a certain amount of playing time. Wiping them down will help and using things like finger ease will help strings last longer. Also the type of frets on the guitar, softer frets do not wear as much as stainless steal frets. I use Dunlop 6150 frets which are big nickel frets. Having bigger taller frets will wear a string down more because I have to push harder on the string, plus I bend a lot and that wears the stings and frets more. I build guitars and have been playing for 40 years.

These have to be some of the dumbest answers I have ever seen, obviously written by novice players. My favorite in the dumb list -- change them when they break! What an idiot. The truth about guitar strings: 1. To a degree, it depends on how much you play. The more you play them, the more often they need to be changed. 2. It depends on your style of play. More aggressive players will need to change them more often because the strings will deaden faster and because aggressive play will make them more prone to break. Many experienced players change strings on a schedule to avoid having a string break during a live show. 3. It depends on the string. Yes, elixir strings hold their tone longer. They also have a more muted tone out of the box because they are coated. So if you like dead strings, elixirs start dead and stay dead longer. Most good players prefer uncoated strings that are about 1/4 the cost of Elixirs. They sound bright for about a month -- then you change them. The cost still ends up being lower and you get consistently better sound. 4. Clapton doesn't play till his strings break. His strings get changed regularly. (See interview with his luthier at http://www.stratcollector.com/newsdesk/archives/000259.html). Yes, he changes them when they break -- which is frequently -- because of his style of play, not because he plays till they sound like crap. Good rule of thumb: if you play regularly, change once a month. If only occasionally, every 3 months. And whatever you do, don't ever play a guitar built by BigDaddy. He doesn't have a clue.