The Tomorrow War. Well advertised on Amazon it's initially set in 2022 where they have found out that in 30 years time civilisation will be wiped out by aliens so hoards of people are drafted up to beam into the future (and back if they survive) to try and find something that can be used to kill the aliens.
The idea is quite a good one, plus add in a complex relationship when the key character goes into the future. My favourite Star Trek episode was the one with Joan Collins in it when they knew her history but couldnt do anything about it so I like themes like this.
In reality though the film is a big let down. Too many silly battles with aliens where key characters never get killed and of course the alien does. If you like yer alien battles then this is for you. But the film could have been oh so much better if they played on the concept more.