If you plan to do a night each for both EU and US/CA I would suggest Monday for US and perhaps Thursday or friday for EU. Or even a weekend day when some US people could make it.
If you only want one night a week, I suggest alternating it and then choosing a weekend day so its possible people from US and EU have a chance to make it on and make it like 2-3pm EST because while it’s relatively late for say, people in Russia, its still a decent hour for them and many would be awake anyway finishing up raids most likely during that time.
So maybe week one you start in US night time like you want, then week 2 is the same day, but earlier in the US day for the Europeans. Then week three is back to US night time, week four bounces back to EU. And while they are alternating, the place is also alternating. So week one us at US night time at the SHI, and week two is in EU raid time or shortly before or shortly after or during, and at the Purple Cap. Week three is US and is at the Conarch Tavern and week four is EU at the tavern in Wild Lands of Zelata or whatever.