England/Scotland for around two weeks?

Stonehedge you say...
😀

If Bath is a there and back day trip from London would put in in the middle of that London block of dates ,rather than face another early start and a " travelling day" up to York.

More time in York

Limit yourself to the just England and Scotland theres a lifetimes worth of stuff to see or you will spend an ungodly amount if time travelling,/ checking in/ checking out and that will be the memory of your trip

I'd actually not try to do a day trip to both Stonehenge and Bath. You'll spend a long time on a bus if you are doing a tour of these. To me Bath needs an overnight if not 2 but it's one place I love and I know others are not that crazy about it.

It's easy to do a day trip to Stonehenge on your own from London. Take an early train from London's Waterloo station to Salisbury. There is a local company that runs a shuttle out to Stonehenge. It's called the Stonehenge Tours but it's not really a tour. Catch this shuttle right outside the train station for a ride out to Stonehenge, then when you are done, meet the shuttle for a lift back in to town via Old Sarum.

https://www.salisburyreds.co.uk/the-stonehenge-tour

I'd suggest not adding Ireland to this trip. I think you are shorting York. If you have extra time, add in nights for Bath and an extra night in York.

Here's where I'd sleep:

London
London
London
London
London
London - day trip to York
Bath
Bath
Bath - day trip (tour) to Cotswolds (instead of Stonehenge)
Edinburgh
Edinburgh
Edinburgh
Edinburgh - day trip (tour) to highlands

There’s no point taking a day trip to York from London to travel back again when heading to Edinburgh.

Bath and Stonehenge (not Stonehedge) can’t really both be seen in one day. Personally, I would opt for a day trip to Bath for the day by train, but don’t do it the day before you head to York. Day 9 - I would take a later train to Edinburgh, as you are short changing York, where you can easily fill 2 full days.

Look at Rabbies tours for the Highlands.

If you are lucky enough to have the 21 days ,you have tons of wiggle room .
As a hopelessly biased northerner who has been to Bath and the equally tricky to pronounce Frome,I hold York to be easily the equal of Bath.
If you have a look on the National Rail site there are quite a few " area" passes which may or may not be useful.

I found York much more interesting than Bath. We went to York on way to London. We took a Rabbies day trip from Glasgow to the Highlands and highly recommend it.

We did a four week drive tour of England and S. Wales. We had been to London before and skipped it. Originally, we planned to go to Scotland as well (we had been to Scotland twice, but never done the western highlands and islands).

After much planning we decided to skip Scotland (another trip some day) and focus on the English smaller towns as well as York. It was wonderful. The British countryside is amazing. Also, Wales has a lot to offer.
We spent three days in York and needed to see all.

thanks everyone for the replies. I mentioned bath and stonehenge (sorry for misspelling it before!) as a same day trip since i saw organized day trips doing that but it seems like everyone agrees that's not a good idea so scratch that one.

It seems like the main thing for me to think about is how many days to allot to Bath and York with some suggesting doing them as day trips from London and others suggesting adding a day (or more) to each. For what it's worth, I'm typically a "fast" traveler who wakes up very early. Let me ask, do trains in England need to be reserved in advance? Or can i stay the night in Bath let's say and decide the next day what time to take the train back to London (in the morning, afternoon or evening)?

For short distances, there’s usually no need to book ahead for a train but I’d definitely book I advance for London-York trains and York-Edinburgh trains. The lowest fares are called advance and tie you to a particular time and date for a train at much savings.

I’d definitely add more time to York. I’ve mentioned that among all my U.K. friends, the only ones who have been to Bath were a couple who used it as a romantic couples weekend away together.

York is one of favorite places in the UK. In fact, I like it better than Edinburgh, which is great as well.
One day is ridiculous for York. There are three museums there that are excellent (one the National Railway Museum). You have the ancient Cathedral that we spent over three hours going through. Walk the ancient walls and so much more.

If you extend to 21-25 days, here is my suggested itinerary: 6 nights in London, 3-4 nights in Bath, 2-3 nights in York, 3 nights Edinburgh, using the rest of your available days for exploring the areas of Scotland that interest you. There is a lot to see in London and the immediate surroundings, all easily accessed with public transit. The train trip to Bath is relatively quick and easy, but I'd suggest spending some time there to really explore that city, plus do side trips to Stonehenge, the Cotswalds, Wells, etc. MadMax tours offers pleasant, reasonably-priced small group trips to these destinations. Then, you have a travel day to York which will require at least one train change. From York you would head north to Scotland.

Besides using guidebooks and online sites to learn about your destinations, you might also read about train travel in Britain and using the bus and Underground in London. The website www.nationalrail.co.uk is a good source of information about prices, discounts, and schedules for train travel. For London mass transit, I like tfl.gov.uk. London does not have a single main rail station, and instead uses a sort of hub system. They are all easily reached by the Underground. I found Bath, York, and most of Edinburgh to be walkable.

As Jennifer pointed out, it makes no sense at all in your case to treat York as a day trip from London, because you also plan to go to Edinburgh. York is almost halfway to Edinburgh. You'll waste both time and money (on train tickets) if you travel London-York-London-Edinburgh rather than London-York-Edinburgh.

Is there a reason you have to stay in London for 8 days?
I will probably take a smacking for saying this but I would hate to be stuck in London for more than a day or two.
My last trip to the UK (and Ireland) was for 7 weeks and apart from transiting through London the only place on your list we visited was Bath and the "Scottish Highlands". We spent 10 nights up there.
There is a lot more to the UK than London and Edinburgh.

ok, so i'm definitely adding another day to York and I think I'll add a day for a cotswolds day trip . I'm still unsure about another day in Bath. So now it's looking:

1. arrive london 2 london
2. london
3. london
4. london
5. london
6. bath day trip
7. cotswolds day trip (from bath or london?)
8. early train to york
9. york
10. york to edinburgh early train
11. edinburgh
12. highlands day trip
13. leave

Wurundjeri, I've never been to London and in addition to non-museum sites, it seems like there are so many museums to go to and each one would be like 3 hours so I thought 5 full days made sense. A half day will probably be a stonehenge trip also.

is just about 2 full days in edinburgh enough? or should i add a day? anything else i should change outside of possibly adding a day for Bath? should i try to spend more time in highlands or will that be too difficult given i don't have a car?

Thanks again everyone for all the help

"it seems like there are so many museums to go to and each one would be like 3 hours"

The British Museum could take a person 5 to 7 full days to see everything, depending upon how quickly you move through the exhibits.

V&A Museum would definitely take an entire day (maybe two) to see everything.

Find out which museums have things you're actually interested in seeing.
Do some research on each museum in London you are considering visiting.
Spend more time in those; skip the ones that have nothing you want to see.

There's really no point in running through a museum, glancing left and right; running, running, as though you're in an episode of "The Amazing Race".
We saw some young tourists in the Tower of London in The White Tower running like this. They literally could not have been running any faster. But I guess they thought they got to see The Tower of London.

I agree that some of the wonderful London museums are huge and you can’t see everything in them. My strategy is to explore their websites to select a few specific galleries to explore.

The day trip destinations you are considering are closer to Bath than to London.

Before devoting 8 days to London in your schedule, try this.
Make a schedule of what you want to see each day in London.

You may find that after you've put all your "must see" sights into an itinerary that 5 or 6 days will be enough to accomplish what you want to see. You won't know this until you make out your schedule.

I agree with Pam.
Bath cannot be fully appreciated without spending one or two nights there.
I agree with Cala.
York is definitely worth spending 2 or 3 nights there. Lots to see and do, even if a person is quick about it, as you say you are.

You are indicating you will fly home from Edinburgh.
Good choice; no need in going back to London just to fly out.
But just in case you change your mind, know that there is an overnight "sleeper" train from Edinburgh to London.

If you want to go to both Bath and the Cotswolds, it makes sense to set up camp in Bath--probably for three nights. There's at least one company doing nice small-group (van) tours of the Cotswolds from Bath, MadMax. That will provide more quality time in the Cotswolds than would be possible by taking a bus tour from London.

It would be prudent to get in touch with the tour company you hope to use well in advance to find out what days the Cotswolds tour is offered. It may not operate seven days a week outside of summer. You might also need to book your spot well ahead of time. I don't know how far ahead, and I don't like to pay for sightseeing tickets farther in advance than necessary, because many of them are non-refundable. Without a car or a tour, it's difficult to see much of the Cotswolds in one day, so this is not the time to start shopping for a tour as you sit on the train from London to Bath.

Scotland by train.

I would think traveling up to Fort William through the grandest scenery ,then heading over to Mallaig ,then to Kyle of Lochalsh and return back on the Kyle-Inverness-Edinburgh would be possible in a day if you just want to watch the scenery roll by.If you could gain an extra day ( looking at you Bath..) then you could spent a night up the Highlands easy enough.
Portree ,Plockton or Mallaig as big a contrast as you could get from all those big city nights you are doing.
If you did the above the 8 day Spirit of Scotland Pass would likely be a good investment,think it's unlimited train travel plus buses and maybe foot passenger ferry too,you'd have to check that .

If you spend two nights in Bath you can do a Mad Max day tour to Stonehenge that probably includes a visit to one of the towns in the Cotswolds. Cotswolds would not be on my list of priorities for a first trip, though.(Neither would Bath or Stonehenge-I would spend more time in York).

Minor detail, but as you plan on departing directly after being in the highlands... Flights to the US can be significantly cheaper out of Inverness than almost anywhere else in Britain. You'd have to connect, of course. (The UK's departure tax is high, but waived for itineraries leaving from 'remote' airports.)

Shop all the options, of course, because fare pricing can be wacky. Just suggesting you look at an option you mightn't have thought of.

With 2 weeks, I would limit the trip to England - stick with at least 5-6 days in London. On my first trip there, I spent 7 days in London and could easily have spent 7 more. And that was with no day trips. After London, take time to see Bath and Stonehenge, York/Yorkshire, and don't forget the Cotswolds. You're not giving yourself enough time to see the countryside and that's one of the best parts of England. There is so much beauty there - don't skimp on that.

Leave Scotland for another trip when you can devote your time to it exclusively. Or add one extra week onto this trip and go to Scotland for 7 days.

thanks for the replies everyone. Here is what i tentatively have:

1. arrive london
2. london
3. london
4. london
5. london
6. london
7. london to bath early
8. day trip to cotswolds from bath
9. bath to york early
10. york
11. york to edinburgh early
12. edinburgh
13. highlands/skye 3 day organized tour
14. highlands/skye
15. highlands/skye
16. leave

how is that looking?

Looks good. Six nights in London may be plenty, depending upon the list of sights you want to see.
I've been to London many times, so my plan for myself would be slightly different.
I would take a night away from London and add it to York.

York is a great place to spend some time even after you've seen the "must see" sights.
Parts of it have an old medieval England look and atmosphere.
London has far less of that, being mostly modern.
I like that York does not have the noise and traffic of London.

Personally, I would forgo a day in London and add back in at least one more day in Edinburgh (or use a few of your potential extra days there). One full day there is not enough! We were supposed to spend three full days there, but due to a 24-hour flight delay, we ended up with only two days. It was definitely rushed and we missed a lot of things we had really wanted to see. It's an incredible city with amazing medieval architecture and history, and I think it's worthy of spending time to explore.

Are you a fan of Georgian architecture or Jane Austen? If not, IMHO skip Bath and give yourself another day to see the Highlands.

as a heads up, I edited my original post to this itinerary which is what I would like to do from around sep 1 to sept 27. Let me know how it looks and if it seems feasible
I'm editing my original post since I already changed my itinerary. Here is what I am looking to do now with a bit of Ireland added in at the end. Hopefully I'm able to make it work:

Day 1 - arrive in London
Day 2 - London
Day 3 - London
Day 4 - London
Day 5 - London
Day 6 - London
Day 7 - Half day trip to Stonehenge
Day 8 - London to Bath early
Day 9 - Cotswolds day trip from Bath (London seems to have more options so might change this)
Day 10 - Bath to York early
Day 11 - York
Day 12 - York to Edinburgh early
Day 13 - Edinburgh
Day 14 - Edinburgh
Day 15 - Highlands 3 day trip (this organized trip exists but doesn't leave everyday, i'll try to make it fit my itinerary)
Day 16 - Highlands day 2
Day 17 - Highlands day 3
Day 18 - Edinburgh to Galway
Day 19 - day trip to aran islands/cliffs of moher
Day 20 - galway to dublin early
day 21 - dublin
day 22 dingle 3 day trip (this organized trip exists but doesn't leave everyday, i'll try to make it fit my itinerary)
day 23 - dingle day 2
day 24 - dingle day 3
day 25 - dublin to belfast early
day 26 - day trip to somewhere from belfast
day 27 - leave

Your Ireland part is in my opinion not possible. How are you getting to Galway? I know you are flying in from Edinburgh but how are you getting from an airport to Galway? Then you are going almost totally across the country East to Dublin then totally across the country West to Dingle. Next across the country East again to Dublin. If you are doing the last part by bus you are looking at a good eight hours. It certainly does not seem enjoyable. Better to save Ireland for another time. This is such a beautiful country meant to be enjoyed. Good luck with your trip.

there's a bus from shannon airport to galway. It's true that Galway to Dublin is totally across the country, it's a rather small country and there are bus and train rides that are 2.5-3 hours. I'm not sure why you consider it such a hard trip. Am I missing something?

The dingle part is a problem and 100% doesn't work through public transportation. If it happens, it can only be done as a 3 day organized trip that starts and ends in Dublin (I found such a trip but it doesn't leave every day. I have to coordinate the trip to make it fit. If it doesn't fit, itll be taken out.

It's a very fast paced trip, that's for sure. You're zig-zagging across the UK (just type it all into the Google Maps route planner) while simultaneously bypassing cities like Manchester or Birmingham. I assume you've got a reason to plan your journey the way you did (you said you prefer the countryside to cities), I'm just throwing it out there.

Why are you planning a whole day for the trip to Edinburgh? It's "only" a 4.5 hour trip – if you take a train in the morning, you'll be there by late midday.

Keep in mind that train travel in the UK can become expensive if you don't book in advance. See nationalrail.co.uk for times and prices.
Also picking up and dropping off a car at different locations often incurs a rather large fee, even if the two locations are geographically close.