Work in legal, can confirm everyone I know that treats their calendar like a to-do list ends up relying on support staff to remind them what /actually/ needs to be done. I calendar datetime events and use a reminder app for everything else broken up by priority (high priority - reminder pops up around 8:00 AM when I get to the office and start my day, mid-priority pops up between 11 AM and 2 PM, low priority pops up after 3 PM).