﴿ وَهُوَ ٱلَّذِى جَعَلَ ٱلَّيْلَ وَٱلنَّهَارَ خِلْفَةًۭ لِّمَنْ أَرَادَ أَن يَذَّكَّرَ أَوْ أَرَادَ شُكُورًۭا ﴾

“And He it is who causes the night and the day to succeed one another, [revealing Himself in His works] unto him who has the will to take thought - that is has the will to be grateful.”

And He it is Who made the night and day to appear in succession that is one succeeding the other for him who desires to remember read yadhdhakkara or yadhkura as before Q. 2550 — so that if he misses the opportunity to do some good during the one he can do it during the other; or desires to be thankful for the graces of his Lord to him during both of these periods.