uk – How does the duration and entry of the Schengen visa work?

I am an Indian citizen with an Indian passport and am planning to travel from New Delhi to the USA and from there to Amsterdam and then back to New Delhi.

I already have a 3-month US visa and am now planning to apply for a Schengen visa for the Netherlands. I had a few questions, please help me.

The current travel route is:

New Delhi -> San Francisco March 20

San Francisco -> Amsterdam March 26th

20 hours stay in London

London -> Amsterdam March 28th

Amsterdam -> New Delhi April 3rd

  1. I have read that the Schengen visa starts on the day you reach the Schengen area. In my case, should I apply for a Schengen visa from March 27th or March 28th because I will be stopping in the UK on March 27th?

I also hope to get a UK visa-free transit, but do you need a Schengen visa the same day?

  1. Will there be problems if I book a round trip from New Delhi to Amsterdam just for a visa application and later travel after my visa according to my plan above?

  2. Are there problems if I travel directly to Amsterdam from the USA without returning to India in between?

  3. Is the immigration officer at the border checking the itinerary we are submitting to the Visa Application Center? Can the arrival or departure dates be changed later (if they are still less than the visa duration)?

  4. Should I apply for a single or multiple entry Schengen visa? Does it have a weight in the visa decision?

Thanks for your help 🙂