20w20a, 20w22a, 1.16 Pre-release 3, 21w19a, 1.17.1
If villagers initiate breeding before going to bed, they will continue to do so if their partner sleeps close to them, and if there are a surplus of beds, they will produce a baby villager. See this video: https://youtu.be/eVeWVGjMvJk
- Place down many beds.
- Spawn a lot of villagers, but make sure that there are more beds than villagers
- /gamerule doDaylightCycle false
- /time set midnight
- Give the villagers lot of bread while they sleep. They will get up to grab it then go back to bed again.
- Quickly set the time to noon and back to midnight.
- The villagers will begin breeding, then go back to bed and continue breeding.
Villagers continue breeding and produce a baby if they sleep near their partner.
Once they fall asleep breeding would be cancelled.