Convert milliseconds to date (in Excel)

Try this best solution :

    This (MsValue / 86,400,000) is used to Converting the value in milliseconds to days 

By using DATE(1970,1,1)  to get 1/1/1970 as a numeric value. 

= (MsValueCellReference / 86400000) + DATE(1970,1,1)

    To get date and time of 19/04/2010 08:16:11 by using the value of 1271664970687 and converting it as dd/mm/yyyy hh:mm:ss 

Use the following link to convert milliseconds to date (in Excel)

Converting unix timestamp to excel date-time forum thread.