How to calculate haiz in Hanafi fiqh

The three numbers behind every haiz ruling

Almost every question about haiz in the Hanafi school comes down to three numbers:

• 3 days: the minimum length of haiz. Bleeding that stops before a full 3 days (72 hours) is not haiz; it is istihaza.
• 10 days: the maximum length of haiz. Nothing beyond 240 hours can be haiz in the same cycle.
• 15 days: the minimum purity (tuhr) between two periods. There is no maximum: a woman can stay pure for months.

Any colour of discharge other than pure white counts as blood during the days that can be haiz: red, black, brown, yellow, green or murky. In the Hanafi school the colour does not decide whether a bleeding is haiz or istihaza; the number of days does.

Step 1: know your habit (aadat)

Your aadat is the number of days of haiz and the number of days of purity in your last valid cycle. For example, if your last period was 7 days and the purity before the next one was 23 days, your habit is 7 days of haiz and 23 days of purity.

In the relied-upon Hanafi position, a habit is established and changed by a single valid cycle. You do not have to wait for a pattern to repeat three times.

Step 2: check the purity before this bleeding

Count the clean days between the end of your last haiz and the start of this bleeding. If the blood came back within 10 days of when your previous bleeding started, the clean days are simply joined to that bleeding (see the 15-day rule). Otherwise, if fewer than 15 clean days have passed, the blood that comes before 15 days are complete cannot be haiz. It is istihaza: keep praying and fasting. Only blood that continues after the 15th clean day can be considered for haiz.

Step 3: see whether it stops within 10 days

This is where most people go wrong. If the bleeding lasts at least 3 days and stops within 10 days, all of it is haiz, even if it is longer or shorter than your habit. Your habit then changes to this new number.

Example: your habit is 7 days. This month you bleed for 9 days and then it stops. All 9 days are haiz, and your new habit is 9 days.

Step 4: if it goes beyond 10 days, return to your habit

If the bleeding continues past 10 days, it is no longer possible for all of it to be haiz. You go back to your habit:

• The days that fall on your habitual days (by timing and number) are haiz.
• Everything before and after them is istihaza. Prayers you missed on those istihaza days must be made up.

Example: habit 7 days of haiz and 23 of purity. This time you bleed for 12 days, starting exactly when expected. Days 1 to 7 are haiz; days 8 to 12 are istihaza.

If the bleeding started early or late, only the part that overlaps your habitual days is haiz, provided it is at least 3 days. If fewer than 3 of your habitual days had blood, your habitual number of days counted from the start of the bleeding is haiz instead. The Haiz Calculator works this out for you and shows each day on a timeline.

What to do while you are still bleeding

You cannot know on day 2 how long the bleeding will last. The practical rule is: when blood appears at your usual time after a valid purity of 15 days, stop praying and fasting. If it comes well before your usual time, check the Before Haiz Calculator. When it stops, make ghusl and resume. If it later turns out the days were istihaza (for example it went beyond 10 days), make up the prayers of those days. If you stopped at fewer than 3 days, those days were istihaza: make up the prayers you missed.

Common mistakes

• Calling extra days istihaza too early. Bleeding a day or two beyond your habit is still haiz if the whole thing stops within 10 days.
• Treating a short clean gap as purity. A clean gap of less than 15 days between two bleedings is not purity; it is joined to the bleeding. See the 15-day rule.
• Judging by colour. Brown or yellow discharge during possible haiz days is haiz in the Hanafi school.
• Not recording times. 3 days means 72 hours. Note the time your bleeding starts and stops, not only the date.
• Forgetting the habit changed. After every valid cycle, update your habit.