OmniFocus allows you to assign estimated durations to actions, action groups, and projects. Estimating how long something will take gives it more definition and helps ensure you don’t take on too much work all at once.
This plug-in provides a convenient way to assign and update estimated durations. There are options to set the estimated duration from as little as two minutes to as long as an hour. Additional commands allow you to add two minutes to one hour to the estimated duration.
For maximum efficiency, create keyboard shortcuts for the commands that you use most frequently. For example, you could use ⌥1 to ⌥ 7 for the seven estimated duration presets and ⌥= to add five minutes to the current estimated duration. This plug-in will work whether you have one or multiple items selected.

