Yes. However, that depends on the availability of the taxi companies operating in your area.
[For version 3.x.x and above]
In the main screen, Select [Reserve Taxi] in the upper part of the screen.
[For version 2.x.x and below]
Booking is almost the same as ordering a taxi.
First set the pickup location, then in the order detail screen,
change [Now] to [Reserve] below the taxi company picker.
After that, select your pick-up time and date.