#define STARTING_AGE 12
/*
#define TICK_SECOND (10)
#define TICK_MINUTE (TICK_SECOND * 60)
#define TICK_HOUR (TICK_MINUTE * 60)
#define YEAR_TIME (TICK_HOUR * 6)
*/
#define YEAR_TIME 216000 //10 ticks/second * 60 seconds/minute * 60 minutes/hour * 6 hours/year = 216000 ticks/year

mob
    var
        birthday
        ages //set to -1#INF to make this mob unaging even if controlled by a player
        tmp
             age = STARTING_AGE
    New() //called automatically when an object is created
        if(!birthday) birthday = world.realtime - YEAR_TIME*age //set the birthday based on the current age
        if(ages&&ages!=-1#INF) Age() //if a non-player mob's prototype has ages set to 1, it will autostart aging without a player

    Read(var/savefile/F) //called automatically whenever an object is read from a savefile
        ..()
        age = round((world.realtime-birthday)/YEAR_TIME) //recover the age based on birthday

    proc
        //this is a loop that keeps track of aging while a mob is loaded.
        Age()
            set waitfor = 0 //keep this from hanging up the caller
            //prevent the loop from executing more than once
            if(ages!=null) return
            var/time = world.time
            ages = time
            var/next_age = birthday + YEAR_TIME*(age+1)
            while(ages==time) //loop as long as this call is current
                if(world.realtime>=next_age) //if our birthday is here
                    ++age //increment age
                    next_age = birthday + YEAR_TIME*(age+1) //set the next birthday
                sleep(world.tick_lag) //we can check this at a lower frequency if we want. That'd be okay.

    Login()
        if(!ages&&ages!=-1#INF) Age() //start the aging loop if needed and not unaging
        . = ..()

    Logout()
        if(!initial(ages)) ages = 0 //if this prototype doesn't age by default, stop aging to allow garbage collection
        ..()