[Remind-Fans] Remind & Birth Control. ;-)

[David F. Skoll]

Dennis Groves wrote:

> First you have to understand the birth control method:

Be aware that this is a very unreliable method.  Also, most women's cycles
are somewhat irregular, so the calendar produced by Remind is very likely
to get out of sync with the woman's body quite quickly.

Anyway... here's a solution.  I offer no explanation, but leave it up
to the list readers to reverse-engineer. :-)

;===================================================================
; The first day of your period
SET period '2008-01-18'

; This is an average!
SET period_len 28

REM [trigger(period)] *[period_len] SCANFROM [trigger(today() - period_len + 5)] SATISFY 1
SET cur_period trigdate()
REM [trigger(cur_period)] MSG PERIOD

SET fertile_start cur_period + 7
SET fertile_end   cur_period + 18

REM [trigger(fertile_start)] *1 UNTIL [trigger(fertile_end)] MSG FERTILE
;===================================================================

> This way I can later generate a yearly calendar that shows what the past
> fertility times were for example. Bonus points if you can put the first
> day of the cycle on the calendar (the day of the period) and the final
> day (day 30) of the cycle as well as the fertile periods.

The average menstrual cycle is 28 days, not 30, although there are significant
variations.  My solution puts the first day of the cycle on the calendar;
it would be trivial to add the last day also.

Regards,

David.