For "all day" appointments (5, 6, 6.5 or 7 hours depending

For "all day" appointments (5, 6, 6.5 or 7 hours depending on location), I'd like to give clients a choice of starting times. i.e. If the ski lifts run from 8:30 am to 4 pm and an all day private lesson is 6 hours, then I'd like to offer starting times anywhere between 8:30 am to 10 am (preferably at :15 minute intervals. When I set up my business hours as 8:30 to 4 pm, it seems like 8:30 am is the only time that comes up.

For 3 hour half day lessons, I would like to fix the starting times to the 8:30 to 9 am and 12:30-1 pm ranges.

Is this possible with appointments+