You get two spears per hour so with all dates planted which is what I did you would be short ten. I then planed a found if rush rooms to finish. Al, crops workout the same now. So if you do pears which are 8 hours you will get 16 for each one and forty for every 20 hour. In my opinion it's not really worth interrupting your normal planting routine. Ie I normally plant dates at night, and usually rush rooms the first hour or two in the morning while I wake up before I switch to grapes if I plan on doing them.