Date Picker Help!

Hello, I am trying to design a basic date picker for my hotel website:

I need literally Select Arrival Date - with drop down calendar
Drop down box of number of nights 1-14 and a Book Now Button

When the button is clicked to book now I need to generate a code to redirect them to my booking engine provider for example: https://booking.welcome-anywhere.net/connect/3739?arrival=2018-11-15&nights=2 That is 15th November - 2 Nights - How can I do this?

The next complication is I also need to submit the URL in YYYY-MM-DD format.

Peter, I have some experience on the subject. For starters, selecting an Arrival Date and then the amount of nights is non-standard: people always make a mistake, because they are counting days, not nights (what the hotel industry is doing). The “normal” way of doing things is offer them 2 date pickers: 1 for day in and 1 for day out. Then you would, in code, calculate the amount of nights between the 2 dates and construct the “nights=2” part of the URL. Look here: JavaScript Date Methods
Your second part, about the date in YYYY-MM-DD-format: this can be done easily, look here: Velo: Formatting Dates | Help Center | Wix.com

Hi Giri, Thank you for your reply - That is very useful! Do you have any advice on the actual coding to get the generation of the URL: Book your stay - Availability search? is always the start point and then depending on the user input generate the end part - I just need some guidelines so I can get this coded as not done anything along these lines before! Thank you once again!