Yesterday I installed Remind after reading the article at 43folders.
I do like to know when the sun rises and sets, but somehow I couldn't get it to work straight away for Amsterdam, NL. The times were completely off. After putting a - in front of the longtitude it turned out fine.
I put this in my ~/.reminders:
SET $LongDeg -4
SET $LongMin -55
SET $LongSec -6
SET $LatDeg 52
SET $LatMin 23
SET $LatSec 26
MSG sunrise at [sunrise(trigdate())],
MSG sunset at [sunset(trigdate())],
MSG next full moon at [moontime(2)] on [moondate(2)]%"%"%