The phrase 'time span of' is correct and usable in written English.
You can use it to refer to the amount of time something lasts for or covers. For example: "The time span of the exhibition was five weeks."
The time span of the offers varies by country.
But what is more striking than the time span of the A.U.M.F. is the geographic breadth.
Their main development took place during the time span of the European Mesolithic.
I call this measure the responsibility time span of the role.
Good transparent GBNPN crystals were obtained in a time span of 3 weeks.
Manager D, with a time span of two to three years, did not feel that C, with a time span of three to four, was distant enough hierarchically to take orders from.
The data show that coke deposition takes place at a time span of tenths of seconds.
The immense size and time span of the Google n-gram dataset allows us to examine this question in detail.
Two numerical simulations were performed on a time span of 3 years.
The charging-discharging stability is also tested for a long time span of 12 weeks.
The time span of happiness is typically short: a good day, a stellar semester, a great year.
