Find first and last day for previous calendar month in VB.Net

Question

Hi!

I'm creating a report in MS SQL Server Reporting Services and need to set the default Start and End Date report parameters to be the first and last dates of previous calendar month and need help.

The report is generated on the 2nd calendar day of the month and I need values for:

Previous Calendar Month
- first day
- last day

I've been working with DateAdd, but have not been successful at creating an Expression (in VB.NET as I understand it). I would really appreciate any help you can give me!

TIA,
Randall

Answer 1

in C#:

new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1).AddMonths(-1)
new DateTime(DateTime.Now.Year, DateTime.Now.Month, 1).AddDays(-1)

Answer 2

Dim thisMonth As New DateTime(DateTime.Today.Year, DateTime.Today.Month, 1)
Dim firstDayLastMonth As DateTime
Dim lastDayLastMonth As DateTime

firstDayLastMonth = thisMonth.AddMonths(-1)
lastDayLastMonth = thisMonth.AddDays(-1)

Answer 3

I'm not familiar with SSRS, but you can get the beginning and end of the previous month in VB.Net using the DateTime constructor, like this:

Dim prevMonth As DateTime = yourDate.AddMonths(-1)

Dim prevMonthStart As New DateTime(prevMonth.Year, prevMonth.Month, 1)
Dim prevMonthEnd As New DateTime(prevMonth.Year, prevMonth.Month, DateTime.DaysInMonth(prevMonth.Year, prevMonth.Month))

(yourDate can be any DateTime object, such as DateTime.Today or #12/23/2003#)

Answer 4

Thanks guys!

I was having some difficulty translating actual VB.NET to the Expression subset that SSRS uses. You definitely inspired me though and this is what I came up with.

StartDate  
=dateadd("d",0,dateserial(year(dateadd("d",-1,dateserial(year(Today),month(Today),1))),month(dateadd("d",-1,dateserial(year(Today),month(Today),1))),1))

End Date
=dateadd("d",0,dateserial(year(Today),month(Today),1))  

I know it's a bit recursive for the StartDate (first day of last month). Is there anything I'm missing here? These are strictly date fields (i.e. no time), but I think this should capture leap year, etc.

How did I do?

Thanks,
Randall

Answer 5

        Dim aDate As DateTime = #3/1/2008# 'sample date
    Dim StartDate As DateTime = aDate.AddMonths(-1).AddDays(-(aDate.Day - 1))
    Dim EndDate As DateTime = StartDate.AddDays(DateTime.DaysInMonth(StartDate.Year, StartDate.Month) - 1)

    'to access just the date portion
    ' StartDate.Date
    ' EndDate.Date