Change Total Animation Play Time

I have an animation that goes for 10 seconds, is there a variable I can change to make it play for 20 seconds instead without going into the play rate? or even a variable I can create that will in turn change the play rate? One possible idea would be to find the total amount of seconds it plays for and thinking I can change that, but I can’t find such a variable.

The reason for this is later on I’ll import an animation that goes for 5 seconds and I’ll want these 2 animations to finish at the same time. It would be nice if there were a variable to control how long they go for.

Is this possible? Thanks