Was looking at ways to get to India for the last week of March using some globals and wanted to consult the experts here for which flight offers the best chance of an upgrade. I'm willing to fly in to and out of either city specifically want to leave on either 3/23, 3/24, 3/25 and arriving back on either the 3/30, 3/31 or 4/1.

I've heard Mumbai is a more touristy destination and Delhi has more official government and business so it might be a harder upgrade?

Since this flight is so far away, there's no practical way of predicting loads and looking at expert mode, most of these flights (EWR-BOM and EWR-DEL) are at best ZN9 but some are even less than that but I assume only because there's no need to load discount business so far out. But would Friday, Saturday, or Sunday fare better for departures in either direction? Any holidays that might be affecting load levels that I don't know about?

Thanks for any advice!