The world's first clock to run on Shaot Zmaniot.
|9:00 sAM||Last time for shma
Last time to eat chametz erev Pesach
|10:00 sAM||Last time for shacharit, most opinions
Last time for biur chametz erev Pesach
|12:00 sPM||Last time for shacharit, if necessary|
|12:30 sPM||Mincha Gedola
Earliest mincha, non-ideal
|3:30 sPM||Mincha Ketana
|4:45 sPM||Plag Mincha
Latest mincha & earliest maariv, according to Rabbi Yehuda
|5:42 sPM||Candle lighting*|
Latest mincha & earliest maariv, according to chachamim
*Candle lighting time is approximate on the assumption that "18 minutes" is not an exact time but instead a general recommendation for "tosefet Shabbat", or adding a few minutes to Shabbat, so you are not lighting candles exactly at sunset. In this case, 18 seasonal minutes will be slightly more than 18 real minutes in the summer, and slightly less in the winter.
Regrettably, and due to forces of nature quite a bit beyond our control, the times before sunrise and after sunset are tied not to seasonal hours, but to the amount of light in the sky, which is a property not of what percentage of the night has elapsed, but of how far below the horizon the sun has sunk.
As a result, it is best to think of these times in terms of "degrees" -- i.e. how many degrees below the horizon the sun is, which directly correlates to how dark it is outside. Think of 1 degree as taking about 4 minutes (true at the equator), although this can vary slightly based on latitude and time of the year. On the iPhone ZmanimClock app, you can get the seasonal and real times for most of these, customized for your location and date.
|Number of Degrees||Approximate Real Minutes||Associated Halachot|
|19.75 degrees before sunrise||79 minutes before sunrise||Alot Hashachar / Dawn, Israeli Minhag|
|16 degrees before sunrise||64 minutes before sunrise||Alot Hashachar / Dawn, Majority Opinion|
|11.5 degrees before sunrise||45 minutes before sunrise||Mishayakir
|6.5 degrees after sunset||26 minutes after sunset||"3 medium stars"
Earliest time to end a fast
|8.5 degrees after sunset||34 minutes after sunset||"3 small stars"
|16 degrees after sunset||64 minutes after sunset||Shabbat Ends, Rabbeinu Tam|
|19 degrees after sunset||76 minutes after sunset||Full darkness|