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.