We don't know when the Time War took place. It has, however, been stated several times (out of universe) that it will always seem to have been in the past of anyone who is aware of it at all.

The Time war happened across all of Time and space. The timeline the new series takes place in is parallel to that, although divergent. Only temporally aware civilisations knew of it. (If you can't understand that, this is the wrong show for you)