The Excel serial date number for July 6, 2016 is 42513.

Notes

  • This assumes the standard 1900 date system used by Excel on Windows.
  • If you meant the 1904 date system , the serial number would be different.

Quick method

For Excel’s common date system:

  • January 1, 1900 = 1
  • Count the days forward to July 6, 2016
  • Result: 42513

TL;DR

July 6, 2016 = 42513 in Excel’s usual serial date format.