About which day in a normal menstrual cycle does rapid secretion of LH (popularly called LH-surge) normally occur?

For women with a 28-day cycle, the 14th day is often the day of ovulation. A surge or sudden release of LH causes ovulation, the release of a mature ovum from the dominant ovarian follicle. After ovulation, LH stimulates the empty follicle to develop into the corpus luteum.