I have tried for a while to get it right...

I need to plot the three birythm curves. The curves start at your birthday, following a sinus waveform and have following periods: emotional curve 28 days, physical curve 23 days and intellectual 33 days.

I need to plot any ones curves for any interval, given the persons birthdate, startdate for the interval and length of the interval.

Anyone that can help on this one?

Rgds, Stefan