function formatDate(format, intTimeStamp)
    dim unUDate, A
 
    ' Test to see if intTimeStamp looks valid. If not, they have passed a normal date
    if not (isnumeric(intTimeStamp)) then
        if isdate(intTimeStamp) then
            intTimeStamp = DateDiff("S", "01/01/1970 00:00:00", intTimeStamp)
        else
            response.write "Date Invalid"
            exit function
        end if
    end if
    
    if (intTimeStamp=0) then 
        unUDate = now()
    else
        unUDate = DateAdd("s", intTimeStamp, "01/01/1970 00:00:00")
    end if
 
    unUDate = trim(unUDate)
 
    dim startM : startM = InStr(1, unUDate, "/", vbTextCompare) + 1
    dim startY : startY = InStr(startM, unUDate, "/", vbTextCompare) + 1
    dim startHour : startHour = InStr(startY, unUDate, " ", vbTextCompare) + 1
    dim startMin : startMin = InStr(startHour, unUDate, ":", vbTextCompare) + 1
 
    dim dateDay : dateDay = mid(unUDate, 1, 2)
    dim dateMonth : dateMonth = mid(unUDate, startM, 2)
    dim dateYear : dateYear = mid(unUDate, startY, 4)
    dim dateHour : dateHour = mid(unUDate, startHour, 2)
    dim dateMinute : dateMinute = mid(unUDate, startMin, 2)
    dim dateSecond : dateSecond = mid(unUDate, InStr(startMin, unUDate, ":", vbTextCompare) + 1, 2)
 
    format = replace(format, "%Y", right(dateYear, 4))
    format = replace(format, "%y", right(dateYear, 2))
    format = replace(format, "%m", dateMonth)
    format = replace(format, "%n", cint(dateMonth))
    format = replace(format, "%F", monthname(cint(dateMonth)))
    format = replace(format, "%M", left(monthname(cint(dateMonth)), 3))
    format = replace(format, "%d", dateDay)
    format = replace(format, "%j", cint(dateDay))
    format = replace(format, "%h", mid(unUDate, startHour, 2))
    format = replace(format, "%g", cint(mid(unUDate, startHour, 2)))
 
    if (cint(dateHour) > 12) then
        A = "PM"
    else
        A = "AM"
    end if
    format = replace(format, "%A", A)
    format = replace(format, "%a", lcase(A))
 
    if (A = "PM") then format = replace(format, "%H", left("0" & dateHour - 12, 2))
    format = replace(format, "%H", dateHour)
    if (A = "PM") then format = replace(format, "%G", left("0" & cint(dateHour) - 12, 2))
    format = replace(format, "%G", cint(dateHour))
 
    format = replace(format, "%i", dateMinute)
    format = replace(format, "%I", cint(dateMinute))
    format = replace(format, "%s", dateSecond)
    format = replace(format, "%S", cint(dateSecond))
    format = replace(format, "%L", WeekDay(unUDate))
    format = replace(format, "%D", left(WeekDayName(WeekDay(unUDate)), 3))
    format = replace(format, "%l", WeekDayName(WeekDay(unUDate)))
    format = replace(format, "%U", intTimeStamp)
    format = replace(format, "11%O", "11th")
    format = replace(format, "1%O", "1st")
    format = replace(format, "12%O", "12th")
    format = replace(format, "2%O", "2nd")
    format = replace(format, "13%O", "13th")
    format = replace(format, "3%O", "3rd")
    format = replace(format, "%O", "th")
 
    formatDate = format
 
end function

http://www.addedbytes.com/asp/vbscript-date-format-functions/

Format strings:

*   %A - AM or PM
*   %a - am or pm
*   %m - Month with leading zeroes (01 - 12)
*   %n - Month without leading zeroes (1 - 12)
*   %F - Month name (January - December)
*   %M - Three letter month name (Jan - Dec)
*   $d - Day with leading zeroes (01 - 31)
*   %j - Day without leading zeroes (1 - 31)
*   %H - Hour with leading zeroes (12 hour)
*   %h - Hour with leading zeroes (24 hour)
*   %G - Hour without leading zeroes (12 hour)
*   %g - Hour without leading zeroes (24 hour)
*   %i - Minute with leading zeroes (01 to 60)
*   %I - Minute without leading zeroes (1 to 60)
*   %s - Second with leading zeroes (01 to 60)
*   %S - Second without leading zeroes (1 to 60)
*   %L - Number of day of week (1 to 7)
*   %l - Name of day of week (Sunday to Saturday)
*   %D - Three letter name of day of week (Sun to Sat)
*   %O - Ordinal suffix (st, nd rd, th)
*   %U - UNIX Timestamp
*   %Y - Four digit year (2003)
*   %y - Two digit year (03)

VBScript Date Format Functions

date

ASP