On Yom Tov (except on Simchat Torah), entire parshiot of the Torah are not read in the synagogue. Rather, select portions of a parsha, generally pertaining to the holiday, are read. These readings are usually shorter than a full parsha.
When a Yom Tov other than Yom Kippur falls on a day other than Shabbat, the reading is divided into five sections (not including the Maftir). On Yom Kippur, six readings take place.
On all these days, the Maftir is read from a different portion of the Torah. Two Torah scrolls are taken out of the ark. This is because it is difficult and time-consuming to roll the scroll to the point where the Maftir is located. The Maftir readings come from the parsha of Pinchas.
The Torah is read on Yom Tov during Shacharit services. There is no reading at Mincha on Yom Tov other than Yom Kippur, unless the day falls on Shabbat, when the regular Shabbat reading for the week is read. The Torah is also read at Mincha on all public fast days.
On the first day of Passover, Exodus 12:21–51 is read. This reading describes the Exodus from Egypt and the Passover offering.
When the first day of Passover falls out on a weekday, the individual readings are as follows:
Reading 1: Exodus 12:21–24
Reading 2: Exodus 12:25–28
Reading 3: Exodus 12:29–36
Reading 4: Exodus 12:37–42
Reading 5: Exodus 12:43–51
Maftir: Numbers 28:16–25
Haftarah: Joshua 3:5–7, 5:2–6:1, 6:27
When the first day of Passover falls out on Shabbat, the individual readings are as follows:
Reading 1: Exodus 12:21–24
Reading 2: Exodus 12:25–28
Reading 3: Exodus 12:29–32
Reading 4: Exodus 12:33–36
Reading 5: Exodus 12:37–42
Reading 6: Exodus 12:43–47
Reading 7: Exodus 12:48–51
Maftir: Numbers 28:16–25
Haftarah: Joshua 3:5–7, 5:2–6:1, 6:27