Translation:Mishnah/Seder Zeraim/Tractate Berakhot/Chapter 4/1

Introduction
The Mishnah, having completed its discussion of the Shema, now turns to the Amidah. In this mishnah, it discusses when the Shacharit (morning), Mincha (afternoon), Ma'ariv (evening) and Musaf (additional) Amidah are to be performed. Practically speaking, this also indicates when the relevant services are performed as the services are developed around the Amidah itself.

Hebrew Text

 * תפילת השחר עד חצות.
 * רבי יהודה אומר: עד ארבע שעות.


 * תפלת המנחה עד הערב.
 * רבי יהודה אומר: עד פלג המנחה.


 * תפלת הערב – אין לה קבע.


 * ושל מוספין – כל היום.
 * רבי יהודה אומר: עד שבע שעות.

English Translation
 Shacharit can be said until midday Rabbi Yehudah says until four hours into the day. Mincha can be said until the evening. Rabbi Yehudah says until the middle of the afternoon. Ma'ariv has no set time. Musaf can be said all day. Rabbi Yehudah says only until seven hours into the day



Explanation
Hours: In Jewish law, an 'hour' is one twelfth of the day (or one-twelfth of the night). Thus, the actual length of an hour varies somewhat depending on the latitude and the current season. There are two opinions about when the day begins and ends: the Vilna Gaon says the day starts at sunrise and ends at sunset. The Magen Avraham says it starts at dawn and ends when 3 stars come out. Midday is, thus, six hours into the day, rather than noon.

No set time: i.e. it can be said all night.

Musaf: There is an additional Amidah on Shabbat, Rosh Chodesh, Rosh Hashanah, Yom Kippur, Sukkot, Shemini Atzeret, Simchat Torah, Pesach, and Shavuot.

משנה ברכות ד א