Use Date & Time in Batch/Log Files

Introduction

Have you ever tried to use date and time in logfiles or batch/command files?
This is not easy without special software. For me, this was a problem because I needed a separate logfile every time an event happened. I also needed this to create backup schedules. The possibilities of batch command are too limited, and different language OS will react differently, so it is hard to roll such batch files out in a multi language OS environment.

Solution

The solution is very simple. I run a VB script where it is easy to get date time and other parameters. These values are stored in environment variables which can be used in batch files.
Because these environment variables are only valid in that particular shell, we need to call the batch file within the VB Script.

Copy the following code in a file called RunNow.cmd:

'***********************************************
'
' RunNow.vbs
' (c) 2008 Computech.
'     Initially Version 2003.
'     2/2/2008 Extra Functionality
' Written by Peter Verijke
'
'***********************************************
Dim dDay, dLDOM, dLDOY, dLFOW, dLFOM
Dim ArgObj
Dim BatchFile
Dim sCommand

Dim WshShell ' as object
Dim objEnv ' as collection
Dim sGetMyVar  ' as string

' Get the Arguments object
Set ArgObj = WScript.Arguments

' Test to make sure there is at least one command line arg - the command
If ArgObj.Count < 1 Then
    DisplayHelpMessage
    WScript.Quit
End If

BatchFile = ArgObj(0)

Set WshShell = WScript.CreateObject("WScript.Shell")
Set objEnv = WshShell.Environment("PROCESS")

dNow = Now()
dLDOM = DateSerial(Year(dNow),Month(dNow) + 1,0)
dLDOY = DateSerial(Year(dNow) + 1, 1,0)
'Friday of this week
dLFOW = (dNow + (5 - Weekday(dNow, vbMonday)))
'Last Friday of Month
dLFOM = (dLDOM + (5 - Weekday(dLDOM, vbMonday)))

objEnv("Year") = Year(dNow)
objEnv("Month") = Right("0" & Month(dNow), 2)
objEnv("Day") = Right("0" & Day(dNow), 2)
objEnv("Hour") = Right("0" & Hour(dNow), 2)
objEnv("Minute") = Right("0" & Minute(dNow), 2)
objEnv("Second") = Right("0" & Second(dNow), 2)

'Day of Week
objEnv("DOW") = Weekday(dNow, vbMonday)
'Day of Week Name
objEnv("DOWN") = WeekDayName(WeekDay(dNow), 1)
'Week of Month
objEnv("WOM") = -Int(-((WEEKDAY(dNow-DAY(dNow)+1, 2) + DAY(dNow) -1) / 7))
'Last Day of Month
objEnv("LDOM") = Right("0" & Day(dLDOM), 2)
'Last Day of Year
objEnv("LDOY") = Right("0" & Day(dLDOY), 2)
'Last Friday of Week
objEnv("LFOW") = Right("0" & Day(dLFOW), 2)
'Last Friday of Month
objEnv("LFOM") = Right("0" & Day(dLFOM), 2)

sCommand = "%COMSPEC% /C " 

WshShell.Run(sCommand + BatchFile) 

WScript.Quit

'************************
'
' Display Help Message
'
'************************
Sub DisplayHelpMessage()
    Dim sHelpMessage
    sHelpMessage = "Usage:" & vbCrLf
    sHelpMessage = sHelpMessage & Wscript.FullName & _
	" RunNow <CommandFile|BatchFile>" & vbCrLf
    sHelpMessage = sHelpMessage & _
	"Optionally use environment variables in file: _
	%Year% %Month% %Day% %Hour% %Minute% %Second%" & vbCrLf
    sHelpMessage = sHelpMessage & _
	"%DOW% %DOWN% %WOM% %LDOM% %LDOY% %LFOW% %LFOM%" & vbCrLf
    WScript.Echo sHelpMessage
End Sub

Usage

As you can see in the source Help Message, it is sufficient to use the environment variables %Year% %Month% %Day% %Hour% %Minute% or %Second% in your batch files. To give an example: you could make a command file called mydir.cmd with the following contents:

dir > MyLog%Year%%Month%%Day%-%Hour%%Minute%%Second%.log 

Instead of running this file directly, run via the VB Script:

RunNow.vbs mydir.cmd 

Now, there are also some extra environment variables like Last Day of Month, Week of Month etc. These variables can also be used for naming or comparing to take other actions in batch files. I use it to create Day, Week and Month Backups for some data.

That's it.

I hope this will be useful to you.