Is the Kyoto station open 24 hours

I will visit Nara and Kyoto in November, I have Hotels booked for both, however I have on night without accommodation on the Sunday 22nd November. I will leave Nara that day for Kyoto. Is it possible to just 'hang around' the Kyoto station overnight on that Sunday?. Unable to book anything in Kyoto or Nara for that Sunday evening.
Thank you.

Consider booking a place in Osaka. You'll be able to get to Nara just as easily.

Yup. Osaka is only like 15-30 mins train ride away from Kyoto. you could also try AirBnb. hanging around outdoors in the cold overnight is not the way to enjoy a holiday...

No. it is not open 24/7

The mall opens about 930ish. The station opens about 6.
Before that it is not open. Staying the night in Osaka, or a city in between Kyoto and Nara are some choices to consider.

The benefits of the former is that Osaka is a major city and it is convenient to get around. The benefits of the latter is that you would be visiting a town that may just become your best experience in Japan. Off the beaten track, hidden gem. If you aren't so adventurous you can stay in Fushimi or Uji.

Some parts of the station building are open 24 hours, not inside the station though. It is not the most comfortable of places, but it is better than sleeping on the street (we have seen that there are homeless people that use it as their home at night when we have passed through in the small hours of the morning.)

Also, that Sunday night is one of the hardest days of the year to get accommodation (even in Osaka). Some booking sites might taunt you with availability, but the rooms are not actually available. (looks like the MyStays has bumped their last room to Y70,000!!)

Rather than Osaka, I would suggest Nagoya - you should be able to get something a little more reasonably priced.

You can certainly look around the station - in fact at night it is actually a very interesting place to see with a lot of free 'shows'.
https://www.youtube.com/watch?v=-XVIFadHzZ8

But if you're suggesting staying up all night or slumming someplace nearby, please don't. Nothing is worse than trying to enjoy yourself the next day when your head feels like a block of cement. Find a place nearby - there are many and something reasonable should be available someplace.

Unable to book anything in Kyoto or Nara for that Sunday evening

I was in a same situation a few years ago unable to get room in Kyoto prior to my arrival due to their koyo season.
However, upon my arrival at Kyoto station, I immediately visited the tourist information office in front of the station. To my surprise, I was shown a list of hotels where rooms were available for the day. I selected one not too far from the station, and problem solved. Apparently, hotels do inform the tourist information office if there is vacancy, could be due to cancellation, especially during the high season. if you are still unable to get accommodation try what I did, do not be surprised you'll get a room.

Thank you everyone for your suggestions, I have indeed tried neighbouring towns and Osaka, the cost for this date is out of my range, mostly there are no vacancies at all anywhere. Will keep on searching, I guess another alternative is to leave my bag in a locker at Kyoto station and look for an all night bar or coffee place.

Suggestion A: Use a manga cafe. They have comfy chairs, blankets, and sometimes a shower.
Suggestion B: Go to spaworld Osaka. They open from 10am to 8am. Meaning you can stay overnight. There are places to rest in there and lockers to use.

I have indeed tried neighbouring towns and Osaka, the cost for this date is out of my range, mostly there are no vacancies at all anywhere

Toyoko inn would be a good try. Osaka ,Shiga, Kyoto are all currently fully booked for your date. But check as often as you can from now till the 22nd Nov. Cancellation is happening all the time, and the probability of getting a room only for one night is very high.
https://yoyaku.4and5.com/reserve/html/rvpc_srchHtl.html?cntry=JPN&chck...

I only hope KIX is open 24 hours. Guess Saturday the 22 is a big deal in Kansai. The previous Saturday I'm staying in Himeji as all Kobe hotels were full back in early September and there were NO Osaka or Kobe options for my last night in Japan. So I'm touristing till the second-to-last Limo Bus leaves Sannomiya for KIX at 10:00; then sleeping in the seating at KIX until my early flight back to LAX. Wont be my first night in an airport and I have clean travel blankets and pillows for the occasion. Gampai!!

Oh yeah that weekend will be busy. National Holiday!

Not sure what your budget is but Airbnb can be your friend.
https://www.airbnb.ca/s/Osaka--Osaka-Prefecture--Japan?checkin=22-11-2...

Still see some reasonable prices. Make sure to read the reviews to decide and then apply to see if host will accept you or not.

I was going to show you the same place I stayed near Imamiya but that place is not available.

Hope this helps!!
Have fun!!