Greetings! Jorg,
“I assume Buddha chose to go into nirodha samapatti as well.”
In the Buddha’s Daily Routine, the Buddha had his nirodha samāpatti at between 4am and 5am.
Piya Tan of Minding Centre had an article on Suppati Sutta (SN 4.7) with details from the commentary that include the Buddha’s Daily Rotine.
With mettā, Seng Kiat