Desk research against primary sources, with the issuing authority linked where a page states an official fee, rule or deadline.
Sequencing the days around geography rather than around a wish list is what actually makes a 4–5 day trip work: cluster Old Dubai and the Creek on one day, the modern icons on another, and treat the beach day and desert safari evening as standalone slots that don't compete with sightseeing time. Trying to fit a bit of everything into each day multiplies transfer time instead of sightseeing time.
The extra days at 7 and beyond are best spent leaving the city rather than adding more inside it, since Dubai's own attractions are largely covered within the first block of days. An Abu Dhabi day trip at 7 days and Hatta or Oman at 10+ days work because they are self-contained additions, not because Dubai itself needs more time to see properly.