Four extra parshiot -- Shekalim, Zachor, Parah, HaChodesh -- read between approximately Rosh Chodesh Adar and Rosh Chodesh Nisan.
The four parshiot (Hebrew: ארבע פרשיות) are paragraphs from the Torah read on four separate Shabbatot from (or before) Rosh Chodesh Adar to Rosh Chodesh Nisan.
- Shekalim שקלים -- Shabbat on or before Rosh Chodesh Adar (Shmot 30:11-16)
- Zachor זכור -- Shabbat before Purim (Devarim 25:17-19)
- Parah פרה -- Shabbat after Purim (Bamidbar 19:1-22)
- HaChodesh החודש -- Shabbat on or before Rosh Chodesh Nisan (Shmot 12:1-20)