Change date time zone

[kz.umair]

I am trying to put a running clock. In cell A1 successfully added running clock which is taking current system time, with the below VB code. However, I want a running clock for EST in B1, CST in C1 and MST in D1. Your healp much appreciated.

Excell file attached... if someone can update in same and attach back, I will be very thankful.

Current System Running clock:

Global clockOn As Boolean
Sub runClock()
Range("A1").Value = Now()
If clockOn = True Then
    Application.OnTime Now + TimeValue("00:00:01"), "runClock"
End If
End Sub
Sub startClock()
    clockOn = True
    runClock
End Sub
Sub stopClock()
    clockOn = False
    
End Sub