How do you know when Geth is synced?

Please help guys. I'm totally frustrated for days here trying every possible thing I can possibly do.

It will get up to the latest block, ahead of any blockchain site, and then it just keeps loading the next block once its found. Does that mean its sync'd? Does the program not tell you anything like "Geth is now synchronized tally-ho!" or something?

I have two computers of very different architectures running this, only similarities would be Windows 10. One pc is an i7 machine, and another is an old socket 775 but with a q9650. The cards are Radeon RX 480s so that is definitely not where the problem lies either.

I have tried things like:

- Syncing time with the internet clock on windows date and time settings

- I've tried removedb upgradedb

- I've tried mining and now it looks like I may possibly be mining its now saying something new "Generating DAG: 52%" i'm hoping this is progress and not one of those times you think you're making progress and actually not. I really hope i'm synced and i'm posting for nothing. That would be phenomenal.

At first the mining said it stopped because of block synchronizations but i'm hopin one of those other options in the help sections will get this stuff synced. The i6 is going through updated so we will see where that ends up as well. On both I basically ended up with the latest block continuously loading after synchronization failed messages in geth.

i'm using the latest Geth Classic v3.3.0