Final answer:
PMS starts during the Luteal phase and ends during the Menstrual phase of the menstrual cycle.
Step-by-step explanation:
The start of PMS (premenstrual syndrome) occurs during the Luteal phase of the menstrual cycle. This phase is characterized by the secretion of hormones such as progesterone and estrogen, and it begins after ovulation.
On the other hand, the end of PMS coincides with the start of the Menstrual phase, when menstruation occurs. The duration of the menstrual phase can vary, but usually lasts around 2 to 7 days.