What is a good alternative for "Date" when talking about range of years?

What the OP refers to as "The range of years denote when someone was working in a specific city" is a typical example of a period.

period (Lexico)
noun

1A length or portion of time.

‘the period 1977–85’

‘The file dates span the period between September 1996 and April 1997.’


Term

a limited or definite extent of time

Tenure and duration are synonyms and are equally as valid.