July has 31 days, so starting from July 8, 2018 up to August 8, 2018, is 31 days.
After than from August 08, 2018 up to August 21, 2018 is 13 days.
Add them together, that puts it at 31 + 13 = 44 days.
Therefore, the time in days from July 8, 2018 to August 21, 2018 is 44 days.