ATCOs working time

[SINGAPURCANAC]

Does anybody know why?
Maximum two hours ,for rdr atcos, followed by minimum rest time...
Max three hours ,for non rdr atcos,followed by minimum rest time...
Maximum working hours are determined for 7/30 consecutive days

Why it is not regulated such as:
rdr atcos may work 6 hours and 11 minutes (e.g :E )
non rdr atcos may work 1 hour and 20 seconds :}
calendar month is month reffered to working hours ...
and so on.

Why in investigation process is always written ,
ATCo has been on duty since last rest ....( minutes and hours )
ATCO has been working in last 7 consecutive days ,so and so hours -among them on frequency ...
ATC has been working in last 30 days....


there must be some connection between those inputs otherwise it will differ significantly among countries (at least we are talking about ANSPs that is paid by CRCO ) .
In my research I found such regulation pretty standardized among ANSPs and I need explanation backbonned by relevant documents.
thanks in advance :ok:

some international regulation (ICAO or Eurocontrol/EASA ) must exists in that context. ;)

[Mamluk]

Even though you expect some logic behind it, the answer can easily be -specifications and bureaucracies live forever :}

Space Exploration History: The Space Shuttle and the Horse's Rear End (http://www.astrodigital.org/space/stshorse.html)

[chevvron]

It differs between different national aviation authorities.
For civil ATC in the UK, it's nominally max 2 hrs on any operational position and 30 min rest for every 2 hours operational, however some very busy units mandate less than 2 hours on position, whilst other less busy units may be permitted to extend to up to 4 hours, but even so they must still have 30 min rest for every 2 hours on duty, with a maximum operational duty time of 10 hours and a minimum of 12 hours between shifts..