Natural Language event timing
Hour by Hour is designed to let you quickly jot down an agenda for your day without fussing with pickers or menus. The fastest way to capture your schedule is simply to write the timing of an event in plain English:
11am coffee with Lisa
...and Hour by Hour will understand, and make a suggestion:

...which you can then accept:

As you type, we use Apple Intelligence to suggest an appropriate icon for your event, so your schedule becomes easier to scan at a glance.
The following is a full list of examples of what Hour by Hour understands:
Simple times
Train at 9am
In the case of ambiguous hours, it will try to choose the most appropriate one given the context:
Walk in the park at 10
You can use both . and : within the time:
2.30pm Meet Bob
14:00 Coffee
As well as words such as:
Lunch at noon
Go to the gym @ midday
You can also use "military" time:
Meet Guinan at 1500 in the mess
Time ranges and durations
9am - 10am
2:30pm to 4pm
3-4pm Pancakes!
Lunch at 2 for an hour
20 min break at 3
Drinks for 1 hour at 9
Note that the following works but you'll also need to enter a start time for it to make sense!
Work till 5
Relative times
Learn more about relative times here.
Arrive half an hour later
After 2 hours - take a break
20 minutes earlier - set off
Wake up 1 hr before
Travel
Splits up into a start and end event with the location names:
2pm Leicester to Edinburgh at 6pm
13.30 London Heathrow - San Francisco 17:00