Using DS3231 Clock Module for project

Evenings, I am working on a project that will use the RTC module as a chronometer. Certain functions on my sketch won’t execute if the time has not reached per say 3 hours. my question is simple, since i am going to be executing this function 6 different times with 6 different “items.” I was wondering if it is possible to create the 6 different chronometers with a single RTC module or if a RTC module would be needed for every single execution of function, since the chronometer for such function is going to be reset after execution.
Excuse my bad english, not my first language.
Best Regards.

You mean a time switch to control a number of separate activities?
You need only one DS3231. In fact, since these have a fixed I2C address you can normally have only one.

Not exactly a time switch, i think(?). Let me explain my project. I have 6 different environments with independent variables (Humidity, Light, Temperature, etc), when all the conditions are meet, a process is going to take place. once this process is done, a timer would go up for that environment in specific. These environment's processes can only take place after a set amount of time has passed, and won't trigger if the chronometer has not reached its set time. Every environment has different periods (3hrs, 6hrs, 5 hrs).

You need only one DS3231. In fact, since these have a fixed I2C address you can normally have only one.

I did not know this. I guess I would have to find a way to use only one RTC module.

Rather than dealing with 6 alarms in parallel, figure out which alarm in the list is closest to to the current time and set that inside the DS3231 or alternatively keep checking the time in the main loop to see if the alarm needs to be triggered. Once that alarm has be triggered you repeat the process for the next alarm by figuring out which one in the list is closest to the current time and so on.

There are probably libraries that do this all for you. Search for 'scheduler library' or something like that.

Another alternative is to use a series of countdown counters that are decremented at regular intervals (1 second or whatever resolution is appropriate). When a counter hits zero then you activate the associated alarm.

You don't need an RTC for this. The Arduino's millis() function can be used for timing and is highly accurate for periods of a few hours. Your code needs to record what time each process occurrs from millis(), then later it can compare the current value of millis() to the recorded value to see if the difference has exceeded the required period.