Muggles presented the following explanation :
On 11/24/2016 1:39 PM, Sterling Archer wrote:
After serious thinking Muggles wrote :
Seventeenth Day of September *in the Year of our Lord* one thousand
seven hundred and Eighty seven


A date naming convention popular in the day. It is nothing more than a
translation from the Latin term: anno Domini (also AD). To imply the
use of this term codifies jesus christ as god and as having any
significance other than establishing the date is disingenuous and
interprative overreach.

The interpretation of why that phrase in there is dependent upon the
perspective you're willing to accept.

It is ENTIRELY possible the phrase represented their acknowledgment of
their belief in Christ as Lord.

Ludicrous.