What is the calculation of days for the iddah of a menopause woman?
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
‘Iddah literal meaning is a calculation, measurement or total number. The reason is it includes the total number of the purity state from menstruation and also the number of months.
The terminology ‘iddah is a name for a certain duration for a woman to wait, enslaving herself to Allah (ta’abbudi) or as a sign of mourning for the loss of her husband, or ensuring that her womb is free from any pregnancy. 
The wisdom behind iddah for the death of a husband is sanctioned is so that:
- Showcasing her loyalty towards her newly passed away husband. Thus, Allah SWT obligates her to respect, stay loyal and treat him well. Thus, it is inappropriate for the wife to act the opposite after the death of her husband.
- Replacing the custom of the jahiliyyah who obligates a widow to lock herself away in a dark place for a year after her husband’s death.
According to the above question, there are two situations for iddah for menopause woman:
- First: Iddah for menopause woman whose husband died
The duration of iddah for a menopause woman whose husband died is four months and ten days. This is based on the statement of Allah SWT:
وَالَّذِينَ يُتَوَفَّوْنَ مِنكُمْ وَيَذَرُونَ أَزْوَاجًا يَتَرَبَّصْنَ بِأَنفُسِهِنَّ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا
“And those who are taken in death among you and leave wives behind – they, [the wives, shall] wait four months and ten [days].” 
The above verse is a general statement that covers all young women whose husbands died where they are all menstruating women as well as for women who have experienced menopause. Hence, iddah for a menopause woman whose husband died is for four months and ten days.
- Second: Iddah for menopause woman who is divorced by her husband
However, if the menopause woman is divorced by her husband, not because of the death of his death, then her iddah is for three months. This follows the statement of Allah SWT:
وَاللَّائِي يَئِسْنَ مِنَ الْمَحِيضِ مِن نِّسَائِكُمْ إِنِ ارْتَبْتُمْ فَعِدَّتُهُنَّ ثَلَاثَةُ أَشْهُرٍ وَاللَّائِي لَمْ يَحِضْنَ
“And those who no longer expect menstruation among your women – if you doubt, then their period is three months, and [also for] those who have not menstruated.” 
Thus, the iddah for a menopause woman is divided into two. Which are if her husband died or if she is divorced by her husband. If she is divorced by her husband, then her iddah is for three months and if her husband died then her iddah is for four months and ten days.
May Allah SWT grant us understanding in understanding this religion. Amin.