Does a woman experiencing menses (Haidh) calculate her menses by the hours of by the Islamic day? 

Q. If a woman’s Haidh period is ten days and she first spotted blood at 2PM on the first day, then does her Haidh period end on the tenth day at 2PM or at Maghrib time? Does she count ten days by hours or by the Islamic day?

A. A woman in Haidh (menstruation) will count her Haidh (menstruation) period from the time she spots blood of Haidh (menstruation). Thus, in doing so, she will not consider the solar or lunar time of day in calculating the Haidh (menstruation) period. She will consider 24 hours as one full day and night by calculating the Haidh (menstruation) period from the exact time i.e. second, minute, hour she spotted the Blood of Haidh (menstruation). (Al-Fataawa-As-Siraajiyyah 49)

Therefore, in the enquired situation, if her Haidh (menstruation) period is ten days and she first spotted blood of Haidh (menstruation) on the first day at 2PM, her Haidh period of ten days will end on the tenth day at 2PM and not at Maghrib time/Islamic day.

Allah Ta’ala Knows Best

Mufti Ismaeel Bassa

themufti.com