The Android app imposes a timeout of 24 hours. We specify this timeout on acquiring permissions from the Android system to keep the device CPU awake during playback. It means that playback, in theory, should continue to play for the entirety of this duration. We don't impose any other time limits on playback.
If Noice stops its playback unexpectedly before this duration is over, it might be because of battery optimisations enforced by the OS. You can disable battery optimisation for Noice by navigating to Device Settings > Apps > Noice > Battery. The exact steps may vary depending on the Android version and device manufacturer.
If turning off battery optimisation for Noice doesn't mitigate the issue, please inform us at firstname.lastname@example.org.