Unable to correctly calculate member revenue.

[KinomotoKi]

If a corp changes the tax rate to 0.1% from the 1st to the 20th of this month,
and then changes the corp tax rate to 100% from 21st to 31st,

the seat-billing will calculate the member revenue based on 'tax rate is 100%' on the 1st to the 31st.

And the right way should be
calculate the member revenue based on 'tax rate is 0.1%' on the 1st to the 20st.
calculate the member revenue based on 'tax rate is 100%' on the 21st to the 31st.

you can use /characters/{character_id}/notifications/ to get character notifications,
look for tax rate change notifications,
and get specific time for tax rate changes,
to match /corporations/{corporation_id}/wallets/{division}/journal/