How far back will mobile sync to a desktop

Shammmo

I have recently had a hard drive failure and am unable to access my most recent data file. I did not realize my iMac was not backing up on Time Machine as I don’t use it much but the wife uses it primarily for Quicken. Our data backup file we have is a little more than a year old. The mobile/online data is current but not backed up anywhere. If I take the old backup and load it on my MacBook and then sync the mobile will it update the old file on the MacBook to the current data? Thanks in advance.
Using Quicken 2017 updated to the latest version in Mac.