I first saw and posted that all 193 flags were Gone - 2 days ago, on Tues. 4/28.
I went by the UN in the early afternoon around 2pm.
4 weeks ago, I was going by that ugly UN bldg. also around 2 pm. and All flags were flying.
I've walked past the UN over the years at all hours, weekday and weeknights, even on Sunday night, so I can tell when something is off. I've seen those flags up even after 4pm.