DateTime Culture

Step 1 import globalization namespace in your class.

Imports System.Globalization

Step 2 Sample Code for thai Language.

Dim pYourCulturrInfo As New CultureInfo("th-TH")

'Get Year format
Dim nYourCultureYear As Integer = pYourCulturrInfo.Calendar.GetYear(DateTime.Now)

'Get all month name
Dim pYourDateTimeFormat As DateTimeFormatInfo = pYourCulturrInfo.DateTimeFormat
Dim sYourMonthName(11) As String

For i As Integer = 1 To 12
sYourMonthName(i - 1) = pYourDateTimeFormat.GetMonthName(i)
Next i

'Get all days in month
Dim nDays As Integer = pYourCulturrInfo.Calendar.GetDaysInMonth(DateTime.Now.Year, DateTime.Now.Month)