Why are all the calendar options in fixed, arbitrary increments?

Why are all of the calendar options fixed in value, rather than allowing an arbitrary value to be entered? 

Example: I can set my default meetings for 5, 10, 15, 30 minutes or 1, 1.5, 2, 3 4 5 6 7 8 9 10, 11, 12, 18, hours, 1-4 days, or 1or 2 weeks. But not 20 minutes (my typical client consult),  50 minutes (typical class, or nominal 1 hour meeting with time to get to the next meeting on the hour) or 5 days (a work-week long event). The drop down selection is so long I have to scroll to see the options, and yet it’s missing many options I’d normally use. Why not offer either a numerical entry field (number, unit like Google does) or (shudder) a silly roller-style selection like phones have?

Example 2: I can set the amount of my day shown on the calendar (number of hours vertically) to 1, 2, 4, 8, 12, and 24.Most people are awake roughly 16-18 hours a day…why is 18 not an option? Better yet, why not let us select a number between 1 and 24? EVEN BETTER - why not put a zoom on your vertical scroll bar, so that the number of hours seen can be dynamically altered whily in calendar view instead of having to go to settings?

eM seems so customizable - this rigidity seems out of place. 

Hello, thank you for your feedback. The result is we added most of the options you requested.

  1. we’ve added 20 and 45 minutes for default meeting option. We will allow a completely custom settings here in future
  2. We’ve added more granularity options for calendar (week view)
  3. we’ve added more Show range options for calendar (10, 15, 18 hours)
  4. btw you can zoom very quickly in calendar ctrl-mousewheel or pin-to-zoom gesture if you have a touch display