Kenya/Tanzania Visa

Looking for some advise on Visas if anybody has knowledge.

I'm travelling to Kenya and staying for 4 days on safari before going on to Zanzibar. I'm then returning to Kenya from Zanzibar and flying back from there to the UK (all on the same day, though with different airlines).

I have my Tanzanian visa sorted no issue just working on the Kenyan one. I understand that within 90 days you can still return to Kenya from Tanzania due to agreements between the country on an eTA.

My question is when applying for the Kenyan visa do I just include the dates when I'm actually staying and forget the travel day? If I include the travel day they expect me to provide locations I'm staying for the full trip which obviously isn't possible due to leaving the country midway.

Appreciate any insight from those who have done similar trips recently.

TLDR: Kenyan visa when staying there for 4 days then returning from a different country 4 days later but only to the airport, what dates to put on the visa?