Help me figure out how Flightaware puts together their urls?

r/Aviation, lend me thy collective wit...

I'm going back and looking up some of my older flights. However some of them are older than Flightaware wants you to look up with the base membership (used to feed ADS-B info, working on reinstituting). Plus it's a pain to search back, so I'm trying to figure out how to put together the URL using the flight information. I've got it mostly figured out.

I'm looking at several flight urls and for the most part the url is put together very logically...

http://flightaware.com/live/flight/UAL1682/history/20170316/1740Z/KSFO/KAUS

http://flightaware.com/live/flight/UAL1682/history/20170708/1732Z/KORD/KMSP

http://flightaware.com/live/flight/UAL1682/history/20170713/1732Z/KORD/KMSP

http://flightaware.com/live/flight/UAL1682/history/20170718/1732Z/KORD/KMSP

http://flightaware.com/live/flight/SWA6541/history/20170705/1120Z/KBWI/KDEN

http://flightaware.com/live/flight/SWA6541/history/20170711/1120Z/KBWI/KDEN

Standard url of website/life/flight/ to start with. Then we have the Carrier and flight number. ... History... Date - YYYYMMDD format. Unknown number/letter combo, Originating airport, destination airport.

Does anyone know what the number/letter combo is? In these examples 1740Z, 1732Z, 1120Z. I've looked and it doesn't seem to be related to the aircraft registration number (different aircraft for different days at times and same number).

Thoughts?

SOLVED

http:flightaware.com/live/flight/ AirlineFlight# /history/ DateYYYYMMDD / ScheduledDepartZulu / DepartCode / ArrivalCode