What do we learn from the fact that this was 45 years later?
Rashi (from Zevachim 118b): We infer that there were seven years of conquest 1 , for the spies were sent in the second year in the Midbar, so there were another 38 years in the Midbar.
This assumes that Kalev said so at the start of the division, after the conquest finished; this Parshah is not out of order. (PF)
Rashi (from Zevachim 118b) writes that there were seven years of conquest. what is the source that there were seven years of division?
Radak (from Zevachim 118b): A verse teaches that Yovel was 14 years after the first Churban (which was 850 years 1 , i.e. 17 full Yovel cycles after entering the land). We must say that they started counting Yovel 14 years after entering, i.e. in all, the conquest and division took 14 years.
Zevachim 118b: Presumably, if the conquest took seven years, also the division did. 2
Rashi (118b): Shlomo built Bayis Rishon 480 years after Yetzi'as Mitzrayim (Melachim 1 6:1). This was 440 years after entering the land, and it stood 410 years.
The Chazon Ish did not understand this. Ben Yehoyada (based on the Ari Zal) - the years of conquest are a Tikun for Rachel, the years of division are a Tikun for Leah. These must be equal, just like Yakov worked seven years for each of them, and other parallels.