As a general rule, take the age of the youngest (for ages 15 through 34)start with the number 10, and multiply that by 1.2 to the nth power, where n=1 for age 15, and increases 1 for each additional year above age 15. That gives you the ideal number of days that should elapse before one can consider a BF/committed relationship. For ages 35 and up, again take the age of the youngest, start with the number 288, and multiply that by 0.95 to the nth power, where n=1 for age 35, and decreases 1 for each additional year above 35, to give the number of days that should first elapse.
If only I could remember high school math (I certainly can remember the gay math teacher) I could have come up with a more precise formula.
Of course this gives an approximation, and one might have to adjust for differing personalities.