VS codeshare with CO

All VS flights to JFK are also CO codeshares as is the evening flight from EWR.
Why is the morning flight from EWR the only one not a CO codeshare ?
Even CO could not tell me this.

Unless I'm mistaken, VS1 isn't a codeshare either.

So it makes sense -- all the JFK flights are codeshares, and they have 1 outbound and 1 inbound sector codeshared to/from Newark -- the outbound is the VS17, the inbound is the VS2.

You've made me wonder why -- I guess because this is what works best with the CO schedules, given they have have a day flight from EWR but nothing leaving LHR in the evening after 1800.

This was how I started thinking until I found that EWR-LHR CO have a flight at 725pm, 910pm and 1010pm - and they also codeshare on the VS flight at 920pm.

I am likely to become obsessed with this until I figure it out !

Me too now!

My imagining of the logic goes as follows:
If they have agreed to codeshare one sector from EWR-LHR (to match just the one outbound sector from LHR [VS17], CO have two choices, either the VS18 day flight or VS2. I guess it must make better commercial sense to opt for the evening flight, despite all their other departures -- the majority of people opt for the red-eyes in order to grab an extra day away.

Thinking about this makes me realise I really don't know anything at all about the value of codeshares to airlines.