Australia's air safety investigators have recommended reforms after a Brisbane air traffic controller was found asleep at his desk while covering an early-morning shift.
_2.3 Night Duty
A period of duty wholly or partly within the period of 0130 and 0529 hours.
2.3.1 Limits on Night Duties
Not more than two night duties may be worked in immediate succession. In all cases the maximum night duty period shall not exceed 9.5 hours and the night duty must conclude no later than 0730 hours.
2.3.2 Interval After Night Duties
Upon the conclusion of two night duties in immediate succession, there shall be an interval of a minimum of 54 hours before the commencement of the next period of duty._
_2.3 Night Duty A period of duty wholly or partly within the period of 0130 and 0529 hours.
2.3.1 Limits on Night Duties Not more than two night duties may be worked in immediate succession. In all cases the maximum night duty period shall not exceed 9.5 hours and the night duty must conclude no later than 0730 hours.
2.3.2 Interval After Night Duties Upon the conclusion of two night duties in immediate succession, there shall be an interval of a minimum of 54 hours before the commencement of the next period of duty._
https://www.civilair.asn.au/news/97-regulation-of-work-hours-for-atc
This guy did the research