Do the morning and evening remembrances have a specific time, and if their time is missed, should they be made up?

The correct view is that the morning and evening adhkar (remembrances) have a specific time, based on the prophetic hadith. Scholars have differed in determining the beginning and end of these times.

The most accurate opinion is that the time for morning adhkar is from Fajr (dawn) until sunrise, and it is permissible to perform them as a make-up until the end of Duha (mid-morning). As for evening adhkar, their time is from Asr (afternoon) until Maghrib (sunset), and it is permissible to perform them as a make-up until one-third of the night has passed. This is supported by the Holy Quran, which encourages remembrance in the early morning and late afternoon.

Ibn Al-Qayyim mentioned that verses such as: ﴿And glorify the praises of your Lord before the rising of the sun and before its setting﴾ [Quran 50:39] and ﴿And glorify the praises of your Lord in the evening and in the early mornings﴾ [Quran 40:55] interpret the hadith, and the place for these adhkar is after Subh (dawn prayer) and after Asr.

Similarly, there are adhkar specific to the night, such as the last two verses of Surat Al-Baqarah, and its night begins from Maghrib and ends at Fajr. If a Muslim misses an adhkar, it is hoped that they will be rewarded for making it up.