UAE & Musandam - 20 days Itinerary

20 days UAE would be a boring trip.
I suggest you combine this trip with a side trip to Oman, a totally different country.
RAK can easily be done in one day, Mussandam in 2. Liwa: depends if you want to venture out in the desert (need camping gear).

I lived in the Emirates for a few years and I agree with henkbos. There just really isn't all that much to see. It is a small country. I'd say 5-10 days max for the Emirates and the rest in Oman. A rental car is the way to go (you would need to inform them if you are planning to include Oman). The drivers are rather crazy... reckless and extremely high speeds... defensive driving is a must.

I have to agree with the first two posters, and say that I too would choose to use at least half of that time in Oman. It is a much more rewarding country for travel.

However, if you want to spend the whole time in UAE, then thats your choice, so in answer to your question, I'd say that:

1. You've given yourself too much time in Abu Dhabi, I'd cut that down to 2-3 days max.
2. Give yourself an extra day or 2 in Al Ain, which has some lovely country to explore, even by saloon car
3. Maybe try and tie the Hatta and Al Ain bits together - they're not that far apart, and the country between the two is lovely.
4. I can understand wanting to limit your time in Dubai, but its an excellent base for much of the rest of the northern emirates, Sharjah especially which is worth at least a couple of days of your time if you are spending three weeks in the UAE. I'd extend to 4-5 days in Dubai.
5. Ras al Khaimah really doesnt have much going on, especially if you plan 4 days in Mussandam, so I'd cut that. Maybe have one night on the way up to Khasab.
6. Kalba ditto - really not much to make an overnight stay worthwhile.
7. Especially in the northern emirates, the distances are pretty small, so you can cover a lot of ground on a day by day basis, and dont need to relocate all the time.
8. I'd condense your plans to something more like this:

1- Abu Dhabi (2-3 days)
2- Liwa Oasis (2-3 days)
3- Al-Ain & Hatta (4 days)
4 - Dubai (5 days)
6- Musandam peninsula (4 days)
7- Khor Fakkan (2 days)

Enjoy your trip anyway.
GC

Unless you have family and friends you want to spend time with and hence the 20 days - cut it down to half, or less than that. Or unless you are looking to escape the winter from whereever you live in which case the scenario slightly changes. If none of the above, my recommendation would be even more short than genghis # 3 above.

1- Abu Dhabi (2 days)
2- Liwa Oasis (3 days including travel)
3- Al-Ain (1 day) (apart from a rocky/ stony hill called Jebel Hafeet and the zoo, not much to make a 4 hour round trip journey there)
4 - Dubai (3 /4 day)
5- Musandam peninsula (2 days max / ie possibly 3 nights) vis Ras Al Khaimah.

Add a few days to your visit to Oman or even venture further out and add a quick trip to a place like Petra or Luxor.

All of the above postings are good; however, I would also advise you to only spend 1 day (maybe 2) in Liwa if you do not plan on venturing out into the desert (ie- if you do not plan on renting a 4x4). There wouldn't be a whole lot to do with a standard vehicle that would take 3 days.

Oh yes good point bri_guy

OP- if you go into the desert, please take a 4 X 4 with properly deflated tires. Better still, if you are not used to desert driving, go with a group. NEVER travel into the desert on your own ie in one vehicle. Even if you go as a group (multiple vehicles), always take extra water with you - and a fully charged mobile phone.

3 Days in RAK? Try 3 hours (or a day if you drive up Wadi Beah. I think you need to research your trip more you'll be twiddling your thumbs half the time there really isn't much to see here.