1/4, 1/2, Full-day rates - this make sense?

[Dinarius]

I want to calculate a daily rate based on €800 per day for a 7 hour day; 4 hours in the morning and three in the afternoon.

Would 1/4 = €250, 1/2 =€450 and 1 day = €800.

I'm trying to incentivize the 1/2 day rate.

What do you think?

Thanks.

D.