The Simple Calculation or Establishment of Paring Day Dates.
First off - you could make up your own calculation to come with dates - or even simply agree a date between the two of you. But when I decided to do it, the simple calculations went like this:
To calculate our family's Pairing Days (FPDs) you need to:
1) First of all take all the family's birthdates, ours are:
Tim (me): 4th February, Wendy: 13th April, Rachel: 28th December, Rowan :25th January.
2) Look which days of the year these dates are on (you can use the Date-Day Look-Up Chart ).
In our case the days are:
Tim: 35th day of the year, Wendy: 103rd day, Rachel: 362nd day, Rowan: 25th day.
3) Then calculate the Family Average Day (FAD), by adding together these figures, and then dividing by the number of members of the family.
For our family, our FAD is (35+103+362+25)/4 = 131st day.
Which is equivalent to the 11th May.
4) Now you are ready to perform the pairing day calculation. It is simply:
Birthdate 1 + Birthdate 2 + Family Average Date = Pairing Day.
So for Wendy and Rachel that would be:
103 + 362 + 131 = 596th day.
Because this is greater than 365 days, we have to deduct 365 days from the total, which becomes:
103 + 362 + 131 = 596-365 = 231st day.
Which when we look up in the Date-Day Look-Up Chart, the 231st day is equivalent to the 19th July.
So, Wendy and Rachel's Pairing Day is 19th July!
5) Now perform the same calculations for all the pair combinations you require.
6) Then create a PD Certificate using any appropriate software and print and distribute copies to each member of the family.
Pairing Days for friends can be calculated in the same way. Simple!