free Timers in Arduino

I am using Arduino Uno and Using LCD, I2C libraries. Now I need some timer interrupts but I dont know which timers are free to use. Does I2c library for RTCds3231 uses any timer.

I dont know which timers are free to use.

There is no cost to use any times.

Does I2c library for RTCds3231 uses any timer.

You are only waving your hands here. A link to the library in question would be a solid fact, not hand-waving.

But, I2C uses interrupts, not timers.

Muphy_S:
Now I need some timer interrupts but I dont know which timers are free to use.

WHY?

The only timer that is used by the basic Arduino system is Timer0 - for micros() and millis().

…R