Convert mm/dd/yyyy to yyyymmdd (VB.NET)

Question

Is there any way I can convert a date of format: dd/mm/yyyy to yyyymmdd format? For example from : 25/07/2011 to 20110725? in VB.NET?

Briony

Answer 1

Dates themselves don't have formats inherently. You can parse a string into a DateTime by parsing it with dd/MM/yyyy format and then convert that into a string using yyyyMMdd format:

DateTime date = DateTime.ParseExact(text, "dd/MM/yyyy",
                                    CultureInfo.InvariantCulture);

string reformatted = date.ToString("yyyyMMdd", CultureInfo.InvariantCulture);

Or in VB:

Dim date as DateTime = DateTime.ParseExact(text, "dd/MM/yyyy", CultureInfo.InvariantCulture)
Dim reformatted as String = date.ToString("yyyyMMdd", CultureInfo.InvariantCulture)

(And make sure you have an import for System.Globalization.)

However, ideally you should keep it as a DateTime (or similar) for as long as possible.

Oldest

Jon, Just curious about this one. Why can't he use String.Format method? – Prober

@reggie: For the second line? He could, but it would be more work IMO. Why specify a compound string format specifier when you only want to format a single value? – Oldest

Thanks for the tip, the second line is what I missed! – Briony

I'm not at all accomplished in vb.net, so please don't take this as a criticism because it is just a question..could be something I'm missing. I understand a little bit about what the whole Culture piece refers to from a semantic standpoint, but from a syntactical standpoint it appears to be completely ... Not accepted, when I try to type it into the SSIS IDE for .net. What am I missing? – Elyot

@Isaac: I don't know anything about the SSIS IDE, but the original answer was only in C#, not VB. I've provided a VB version as well now. Make sure you've imported the System.Globalization namespace. – Oldest

Answer 2

 CDate(Datetext).ToString("yyyyMMdd")

Mosaic

This answer could fail depending on the culture. That's why Jon's answer is better than this one. For example, how would decide if 10/12/2017 is 10th December or 12th October without the ParseExact? – Farinaceous

Answer 3

Use the DateTime.ParseExact method to parse the date, then use DateTimeObj.ToString("yyyyMMdd").

DaTeTime.ParseExact

Inkwell

Answer 4

Public Function DateFormateYYYYMMDD(ByVal Dtp As DateTimePicker) As String

   Try
      Dim StrDate, StrYear, StrMonth, StrDay As String
      StrDate = FormatDateTime(Dtp.Value, DateFormat.ShortDate)
      StrMonth = Month(Dtp.Value)
      StrDay = Convert.ToString(Dtp.Value.Day)
      StrYear = Year(Dtp.Value)
      StrDate = StrYear + "-" + StrMonth + "-" + StrDay

      Return StrDate
   Catch ex As Exception

   End Try
End Function

this function can be used to convert datetime picker value format to yyyyMMdd

Peremptory