die Arbeitszeit
working hours
The period of time during which a person performs, or has to perform, their professional duties.
Meine Arbeitszeit beginnt um 9 Uhr und endet um 17 Uhr.
My working hours begin at 9 a.m. and end at 5 p.m.

working time
Loading your saved state.
working hours
The period of time during which a person performs, or has to perform, their professional duties.
Meine Arbeitszeit beginnt um 9 Uhr und endet um 17 Uhr.
My working hours begin at 9 a.m. and end at 5 p.m.

'Arbeitszeit' (working time) is a compound noun made up of 'die Arbeit' (work), the linking -s, and 'die Zeit' (time). The meaning is literally 'the time for work'.
Die gesetzliche Arbeitszeit darf nicht überschritten werden.
The legal working time may not be exceeded.
Common verbs are 'die Arbeitszeit verkürzen' (to shorten working time), 'verlängern' (to extend it), 'erfassen' (to record it), or 'einhalten' (to comply with it). Typical adjectives are 'flexibel' (flexible), 'fest' (fixed), or 'reduziert' (reduced).
Viele Mitarbeiter wünschen sich eine flexiblere Arbeitszeit.
Many employees would like more flexible working hours.
The exact meaning often becomes clear from context. A statement with 'von ... bis ...' (from ... to ...) usually describes the daily schedule. A statement with '... Stunden pro Woche' (... hours per week) describes the total contractual duration.
Meine Arbeitszeit ist von 8:30 Uhr bis 16:30 Uhr.
My working hours are from 8:30 a.m. to 4:30 p.m.
service / duty
'der Dienst' and 'die Arbeitszeit' can both have to do with the time when someone works. 'Arbeitszeit' directly means the period of time or the fixed duration of work, for example eight hours a day or 40 hours per week. 'Dienst' is more about the specific work period or assignment, especially when someone is working on a particular day or in a particular shift. Learners may confuse the words because both can fit questions like 'Wann arbeitest du?' (When are you working?). If you are talking about hours, starting time, ending time, or rules, 'Arbeitszeit' is more precise. If you want to say that someone is currently on duty, 'Dienst' fits better.

Nach der neuen Regel endet die Arbeitszeit freitags schon um 14 Uhr.
Under the new rule, working hours end at 2 p.m. on Fridays.
Mila hatte am Montag Dienst, obwohl viele andere frei hatten.
Mila was on duty on Monday, even though many others had the day off.