This code calculates the **last Friday of the current month**...

This code calculates the last Friday of the current month using the following steps:

1. Determine the number of days in the current month:

   var daysInMonth = DateTime.DaysInMonth(now.Year, now.Month);
   

   This gets the total number of days in the current month based on the now.Year and now.Month.

2. Get the last day of the current month:

   var lastDay = new DateTime(now.Year, now.Month, daysInMonth);
   

   Creates a DateTime object representing the last day of the current month.

3. Calculate the date of the last Friday:

   var lastFriday = lastDay.AddDays(-(int)lastDay.DayOfWeek - 2);
   

   • lastDay.DayOfWeek returns the day of the week for the last day of the month (e.g., DayOfWeek.Sunday has an integer value of 0).
   • Subtract (int)lastDay.DayOfWeek + 2 days from lastDay. This adjusts the date to reach the last Friday based on the following logic:
     • If lastDay is Sunday (0), this subtracts 2 days to get to the last Friday.
     • If lastDay is Monday (1), it subtracts 3 days, and so on.

4. Check if the calculated Friday is still in the same month:

   if (lastFriday.Month != now.Month)
   {
       lastFriday = lastFriday.AddDays(7);
   }
   

   If the calculated lastFriday falls in the previous month (this may happen if the lastDay subtraction missed the last Friday), the code adds 7 days to move to the correct Friday in the current month.

Output

After execution, lastFriday will contain the date of the last Friday of the current month.