If at least six of the men in a mincha minyan on a fast day are fasting, read the Torah portion Va'yechal (Exodus 32: 11-14). If fewer than six are fasting, omit it.

Say “sim shalom” instead of “shalom rav” at mincha on a fast day, even if you are not fasting at mincha.

Plag HaMincha: 1 1/4 halachic hours before sunset until sunset.

Mincha Gedola: 1/2 hour after halachic midday until 2 1/2 halachic hours before sunset.

Mincha Ketana: 2 1/2 halachic hours before sunset until sunset.  

Tzeit HaKochavim: 36 to 72 minutes after sunset, depending on the opinion, purpose, and geographical location.
 

Ma'ariv may be said from sunset (or even from plag ha'mincha if mincha was said early enough).

It is an enhancement of our prayers to give charity at shacharit and mincha (except on Shabbat and Jewish festivals).

You may not light Shabbat (or Jewish festival) candles before plag ha'mincha. The candles must burn until at least dark (tzeit ha'kochavim) and someone must be there to see the light from the candles after dark.
SITUATION Mincha minyan begins at plag ha'mincha. You cannot light candles at home and still get to mincha minyan on time.
WHAT TO DO You must say mincha on your own (anytime from half an hour after mid-day until sunset). You will light candles after plag ha'mincha but before sunset and not join the mincha minyan.

You may not light Jewish festival (or Shabbat) candles before plag ha'mincha.  The candles must burn until at least dark (tzeit ha'kochavim) and someone must be there to see the light from the candles after dark.
SITUATION  Mincha minyan begins at plag ha'mincha. You cannot light candles at home and still get to mincha minyan on time.
WHAT TO DO You may light a candle without a blessing, just so you can have a flame for after the festival has begun. You go to synagogue and after ma'ariv you return home and light the candles from the flame which was burning from before sunset. If you will not have a flame burning from before sunset, you must say mincha on your own (anytime from half an hour after mid-day until sunset). You will light candles after plag ha'mincha but before sunset and not join the mincha minyan. Women should skip mincha and light candles either 18 minutes before sunset or have a flame burning from before sunset and light candles from that flame once the festival has begun (but she may not light from a new flame or a match).

Say avinu malkeinu, even if you are praying by yourself, after amida of shacharit and mincha on:

• Public fast days, and
• Between Rosh Hashana and Yom Kippur.

You may say ma'ariv on Friday afternoon (erev Shabbat) as early as plag ha'mincha (1 1/4 halachic hours before sunset), as long as you say mincha before saying ma'ariv. So, if it is now plag ha'mincha, you may say mincha and then follow it as soon as you wish with ma'ariv.

You may say ma'ariv before the start of a Jewish festival as early as plag ha'mincha (1 1/4 halachic hours before sunset), even if you did not say mincha before plag (unlike on weekdays when you must say mincha before plag in order to say ma'ariv before sunset). 
 

If you began the Jewish festival early and you are at a minyan where they are saying kedusha for mincha before the Jewish festival, you should reply to kedusha.

The ideal time for ma'ariv on Friday night is whenever will make everyone (or most people!) happy. It can be any time from plag ha'mincha (1 1/4 halachic hours before sunset), until 72 minutes before sunrise, but should properly be said before midnight.

To say hallel on Shabbat and Jewish festivals:

• You do not need to say full hallel immediately after shacharit.
• You may say musaf and/or hallel after mincha.
• Once it is time for mincha, you must say mincha before saying musaf or hallel (if you have not said musaf or hallel yet).

You may not do any work or get involved in any project that might distract you from preparing for Shabbat, beginning at twice the duration of plag ha'mincha.  So allow 2 1/2 halachic hours (sha'ot zmaniyot) before sunset to prepare for Shabbat.
 

You may not do any work or get involved in any project that might distract you from preparing for a Jewish festival, beginning from twice the duration of plag ha'mincha.  So allow 2 1/2 halachic hours (sha'ot zmaniyot) before sunset to prepare for the Jewish festival.