Subtract one month from Datetime.Today

Question

I have a DateTimePicker in which I allow user to select month previous to the current year.

The problem is, that if the date is 1st January, it can't calculate the December month of last year in the way I am doing it now.

var today = DateTime.Today;  var lastmonth = new DateTime(today.Year, today.Month - 1, 1); if (qs == "") {     dateTimePicker1.MaxDate = lastmonth;     dateTimePicker1.Value = lastmonth; } else {     DateTime dt = Convert.ToDateTime(qs);      dateTimePicker1.Value = dt;     dateTimePicker1.MaxDate = lastmonth; } 

Answer 1

Just substract a month by 'adding` -1:

var lastmonth = DateTime.Today.AddMonths(-1); 

See the MSDN documentation on DateTime.AddMonths.