How long would it take to travel ~145 miles by foot?

Say that it is during Summer ~25-30 degrees celsius and across mainly sub-desert terrain such as southern Spain. Something close to being Almeria to Murcia. One would of course have to stop for rests and sleeping. How many days would it take? Please also can you factor in that walking rate will not be at a constant throughout the day. Cheers! Much obliged!