Question

I want to count data of each day from database using the for loop. Here, I don’t know to get the begining of day (start from 12 am) and end of that day ( 12 pm) from value of only date. In below code startDate and endDate have only date value e.g. 2/11/2012.

for (DateTime dates = startDate; dates <= endDate; dates.AddDays(1))
{
    DateTime BeginingOfDay = begining of value variable dates; // 2/2/2012 00:00:00
    DateTime EndOfDay =  at end of value variable dates; // 2/2/2012 23:59:59
    int count = (from u in db.CDRs where (u.StartTime >= BeginingOfDay && u.StartTime <= EndOfDay) select u).Count();;

    dictionary.Add(dates.ToString("MM/dd/yyyy"), count);
 }

Answer 1

The best way to deal with this is to use the right combination of lessthan/greaterthan operators with midnight on day n, and midnight on day n+1

so given a day, eg

var date = new Date(2012,8,24); // today

get midnight on that day (start of the day)

var start = new Date(date.Year, date.Month, date.Day, 0,0,0); // could also be date.Date

and to get midnight on the next day just add 1 day

var end = start.AddDays(1);

now use greater-than-or-equal-to for the start, and less-than for the end:

var inRange = x.StartTime>=start && x.EndTime<end

Put together into your example becomes:

for (DateTime dates = startDate; dates <= endDate; dates.AddDays(1))
{
    DateTime BeginingOfDay = new DateTime(dates.Year,dates.Month,dates.Day,0,0,0);
    DateTime EndOfDay =  BeginingOfDay.AddDays(1);
    int count = (from u in db.CDRs where (u.StartTime >= BeginingOfDay && u.StartTime < EndOfDay) select u).Count();;

    dictionary.Add(dates.ToString("MM/dd/yyyy"), count);
}