Ninjas last till the end instead of the beginning of next Ninja Event

All war/ conquest boosts last till the end of the next war/conquest, so it doesn’t leave any gap. I suggest for Ninjas to have the same concept so there won’t be a ‘gap’ where there’s no ninjas/ yeti/ zombies.

Conquest boosts last a week. I think war boosts too. Ninjas last longer but not sure about a gap or not.