Past days or Passed days?
Generally, you would write "the past few days" but does writing "the passed few days" make sense too? The answer is context. Here's a way to distinguish between the two.
the past few days:
From some point in the past - to → today/present
the passed few days:
A range of days in the past, could be any range.
Example: last Friday - to → present or Jan 01, 2021 - to → Jan 05, 2021