Question: how to calculate number of days between two dates with time?
Answer: =DATEDIF(DATE(2015,3,23),"4/27/2017","MD") - the function calculates the number of days between March 23, 2015 and April 27, 2017 ignoring months and years, i.e. it returns the difference in days between the 23-th and 27-th day. The result is 4 days.