Your math is off, here's my schedule:

Sunday 10pm - Tuesday 10am - No food.

Tuesday 10am - Tuesday 10pm = 1500

Tuesday 10pm - Thursday 10am = No food.

Thursday 10am - Thursday 10pm = 1500

Thursday 10pm - Saturday 10am = No food.

Saturday 10am - Sunday 10pm = 3000 (Sat 1500cal, Sun 1500cal)

6000cal.

Though I agree there probably is some fuzziness in those 1500 days that I'm not properly accounting for.