Relative times and durations
In Hour by Hour, there are two ways to specify times for events:
- Fixed: the standard way, using clock time.
- Relative: a number of minutes before or after an adjacent event.
For relatively timed events, the time offset (such as "14 mins before" or "30 mins later") is highlighted in colour, whereas fixed timed events highlight the actual time.
Relative events are tied to the event before or after them. You can chain multiple relative events together, and just like a spreadsheet formula, changing one time will automatically update all the others in the chain.
Create a relative-timed event using natural language
Type a relative time phrase in your event title:
Set off 30 mins before
Accept the timing suggestion, and you're done. Learn more about natural language input.
Creating events with durations
Similarly, you can create events with durations using natural language:
1 hour meeting at 3pm
This actually creates two events: a fixed event at 3pm called "Meeting", and a relative event that's 1 hour later. The second event doesn't need a title - it simply marks when the first event ends. You can also create this structure manually if you prefer, but natural language is usually the easiest way.
Convert an existing event to use relative timing
Press and hold on the time, then choose one of the "Relative to" options. To switch back, press and hold again and choose 
Make time fixed.
When events automatically convert to fixed
Sometimes Hour by Hour needs to convert an event back to fixed timing automatically. For example, if you have:
- 08:00 Flight departs
- 10:00 Flight lands (2 hours later) — relative time
...and then:
- Convert "Flight departs" to relative — so, 2 hours before the landing time. The landing time will automatically convert to fixed.
- Insert an event in the middle — like 9:00 Eat snack. This breaks the relative chain, making all times fixed.
Importing calendar events can also break relative chains in similar ways by inserting new events between relatively timed ones.