.net get the first and last day of week

Sample code :

Dim dt As DateTime = DateTime.Now
Dim wkStDt As DateTime = DateTime.MinValue
Dim wkEndDt As DateTime = DateTime.MinValue
wkStDt = dt.AddDays(1 - Convert.ToDouble(dt.DayOfWeek))
wkEndDt = dt.AddDays(7 - Convert.ToDouble(dt.DayOfWeek))
Response.Write(wkStDt.ToString("MMMM-dd") & "<br/>")
Response.Write(wkEndDt.ToString("MMMM-dd"))

keyword : first day of week, last day of week, vb.net, .net