When does the iddah (waiting period) for my mother's deceased husband, who passed away on April 23rd, end?

If the mother is pregnant, her 'iddah (waiting period) ends when she delivers her entire pregnancy, based on Allah's saying: "And for those who are pregnant, their term is until they deliver their burdens."

If she is not pregnant, her 'iddah is four months and ten days, based on Allah's saying: "And those of you who die and leave wives behind - they, [the wives], shall wait four months and ten [days]."

The 'iddah begins from the time of death, and its calculation is not by solar months but by lunar months. Therefore, if your father passed away on April 23rd last, it is necessary to determine the corresponding Hijri date in your country, as the 'iddah is calculated by moon sightings, whether they are thirty or twenty-nine days.

The calculation of the 'iddah begins from the moment the husband passed away, according to the majority of scholars. However, according to the Malikis, the day of death is not counted if it occurred after dawn.