Two shifts, and where they overlap
They are asked a question when they go up.
يَتَعَاقَبُونَ فِيكُمْ مَلاَئِكَةٌ بِاللَّيْلِ وَمَلاَئِكَةٌ بِالنَّهَارِ، وَيَجْتَمِعُونَ فِي صَلاَةِ الْفَجْرِ وَصَلاَةِ الْعَصْرِ
Yataʿāqabūna fīkum malāʾikatun bi-l-layli wa malāʾikatun bi-n-nahār, wa yajtamiʿūna fī ṣalāti-l-fajri wa ṣalāti-l-ʿaṣr
“Angels take turns among you, some by night and some by day, and they come together at the dawn prayer and the afternoon prayer.”
Where this comes from
Then those who stayed the night go up, and He asks them, though He knows better, how they left His servants. They say: we left them praying, and we came to them while they were praying.
The full narration
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "Angels come to you in succession by night and day and all of them get together at the time of the Fajr and `Asr prayers. Those who have passed the night with you (or stayed with you) ascend (to the Heaven) and Allah asks them, though He knows everything about you, well, "In what state did you leave my slaves?" The angels reply: "When we left them they were praying and when we reached them, they were praying
Source
Ṣaḥīḥ al-Bukhārī · 555
- Agreed upon as authentic (al-Bukhārī / Muslim)