Question

 Stores everywhere compete to sell their own unique cakes in the days leading up to christmas  

((why did the writer used (in) for the days ? 

Answer 1

سلام. با توجه به توضیح ارئه شده در لینک زیر می شود از in یا on استفاده گردد ; ولیکن با یک فرق جزئی :

https://www.google.com/url?q=https://forum.wordreference.com/threads/on-in-the-remaining-days.2746702/&sa=U&ved=2ahUKEwi35JG-sOTmAhUPGuwKHWCLArkQrAIwB3oECAUQAw&usg=AOvVaw1fvWbpzux0mkrTmLThN9hH

Thank you. I think I could say either there.

'On' tells me that shopping took place daily in what was left of your trip. 'In' seems more vague - shopping took place on one or more of the days that remained.