Tough to choose, but I think it would be interesting to see what the heck was going on with the dancing plague of 1518.

Would I still be able to remember the visit? Witnessing the hiding of some long lost treasure would still be directly beneficial.

The start of the universe. The big bang, or even what came before that. The big dinner and a movie.

The conception -- not birth -- of Jesus. Assuming God doesn't show up, I'm still watching two human beings go at it, and that's kind of fun on its own.

I had heard that Mark Twain was a fantastic orator, so I would love to be in the audience for one of his shows.

Normandy Beach, D-Day. You read about the scale, but to see it in person...

Either watch the building of the Tomb of Tutankhamun. Watch and record what happens. I can't interact or interfere (which mean I would have zero effect on the time line), but I would have video evidence of how they did it. Since it took years to build (supposedly) we don't really know how long it took, I would watch the beginning week or two of it.

Be a hell of a shock if it really was "aliens". lol

I wanna witness the Roman who graffitied about being gay in the bathroom stall - just to see the kind of man they were.

Darmok and Jalad at Tanagra

I'd like to see the asteroid that finished off the dinos and Mount Vesuvius erupting.

I would love to see the moment humans first learned complex speech patterns. Yes it was probably a long process. But to see the first complete sentence uttered would be cool as hell. Even better if I could somehow understand it.

The big bang, especially if I can record it (don't think that counts as interacting, it's just a more trustworthy version of the recording it into my memory)

Especially since this means we'd get the conditions before it

Can I watch the first moon landing from the moon? Or maybe one of the big astrod impacts....

I think it would be a toss up between attending the sermon on the mount and spending a day in America before Columbus landed.

I'd probably choose something for entertainment. Maybe see what a Shakespeare show at the Globe was really like (extremely chaotic from what I've read)

Or see Hendrix play live at Woodstock!

That makes me sound a bit shallow maybe - there's a lot of questions I have about what early Christianity was like before the Catholic church came on the scene, what sort of a ruler Richard III was, similar sorts of dry questions... But given the choice I'd probably want some rowdy entertainment

Can I move around and replay and can I watch at speed multiples like 100x? There are so many land formations I'm interested in seeing formed. From major things like chimney rock to a creek at home that's 200ft below the hill tops alongside it. If it's only for one event I choose the end of the last great ice age. If I only get 24 hours real-time I choose observing Hitler the 24 hours before he killed himself.

I want to see a day during the Cambrian explosion

The construction of the pyramids in Egypt.

I've grown increasingly convinced Nefertiti served as inspiration for later stories about Helen of Troy, so I'd very much be interested in seeing the arrival of "beautiful woman who arrived" at Pharoh's court, and the way the only woman ever depicted in the smiting pose in Egyptian history carried herself into a dangerous new environment.

What charm and wit did she possess such that Akhenaten felt the need to both acknowledge in the boundary stelae at Armana that she got everything she desired but to adamantly deny that the idea for the city was hers?

How much of reworking the entirety of Egypt's religion into a solar cult was the result of her influence, and just how did she see her role in that paradigm?

I have many questions about her that I'd probably have answered with 24 hours of being a fly on the wall observing her and her husband's interactions.

The fall of the Colossus of Rhodes or the Assassination of Julius Caesar.

Record that lost speech of Lincoln.

@MariaRomanov the buddh’s enlightenment

the death and or funeral of ghengis khan

D-Day, somewhere were the scotsmen landed. Imagine hundreds of planes in the air, thousands of ships, the soldiers take the beaches and behind them a bagpiper is playing.

Would like to witness the Ides of March, from the beginning of the day till the end.

I'd love to see Hannibal crossing the Alp's with elephants! and if I had only 24hrs i guess it would be at the point they emerge from the mountains and romans see the elephant sand shit themselves. (I'm not sure that part ever happened)

Jesus Christ and the sermon on the mount, specifically the sharing of fishes and loaves of bread.

I will kick the first lungfish back into the primordial sea.