How to estimate the number of days a place can be fully renovated?

As a General Contractor I start with estimating how long it will take to do the following, some things I use subcontractors on. A subcontractor must tell me their schedule prior to me presenting the owner with a time period for completion.

#1. Demo - time to remove walls/flooring/wiring/hvac - Time to frame new walls

#2. Electrical - new wiring/modify existing/lighting-rough in

#3. Heating/Ac

#4. Internet/Data lines/cat5 wires/Tv/Phone

#5. Drywall finishing/Prime Paint

#6. Doors interior or entry

#7. Floor coverings

#8. Trim/Base mold

#9. Trim out electrical /Install lighting fixtures

#10. Set any counters/displays

This is what I go through on each and every job.

Small spaces are harder to co-ordinate, but it works well if you get organized.

Too many factors to give a good estimate without seeing property. Hire a local contractor. They'll take off the cost of the estimate when the work gets contracted. Also keep in mind unforeseen circumstances such as having to update to code electrical or structure that may not be quite right. etc.