What is calendar runway?

A worked example

Sam Ellis, who runs sales at Meridian Systems (a fictional company), owes Northstar a commissioning report. It is Monday morning, and the report is due on Friday week.

Days until the deadline	11
Working days among them	10
Working hours in those days (09:00–17:30)	85 hours
Free time left once the meetings are counted	3.5 hours, in 3 gaps, plus 1 twenty-minute gap that is too short to count
What Sam estimates the report needs	6 hours
Runway	3.5 hours free for 6 hours of work: insufficient

Radar puts the reason on the report (“Insufficient runway: 3.5h free for 6.0h of work”) and counts it towards the report’s risk, so it stands out on the radar while it is still 11 days out. On a plain task list it would still look comfortable for another week.

Why days remaining misleads

Days remaining treats every day as empty. Most working weeks are not: meetings, travel and the work already promised to other people take most of them, and what is left arrives in scraps. Eleven days with three and a half free hours is a different job from eleven empty days, and the difference only shows up when the diary is in the sum.

How Radar works it out

• Free time is your working hours (09:00–17:30, Monday to Friday) up to the end of the deadline day, less every busy event in your connected calendars. Events marked free or working elsewhere, and all-day events, do not count as busy.
• Gaps shorter than 30 minutes are ignored: nobody writes a report in twenty minutes between calls. A gap of an hour or more counts as a work window, and Radar warns when only one is left.
• The estimate is yours. You say how many hours the work needs when you put it on your Radar, and as you record progress Radar counts only what is left: 6 hours at 50% done is 3 hours still to find.
• Correcting it is editing the estimate or the progress. Radar never changes either on its own.
• The verdict: less free time than the work needs is Insufficient; less than a quarter more than it needs is Just enough; anything else is Sufficient, and once every hour is booked it is All reserved. When it is short, Radar says how many hours are missing and by when. Runway is worked out for the next 45 days, where the calendar is still a fair picture of the week.
• Booking the time is one press. Radar suggests focus blocks, as one sitting or sessions of up to two hours; take one, press Reserve all, or choose times yourself on a week-to-a-page grid. With Outlook or Microsoft 365 it puts them in your calendar, says first if one overlaps something already there, and never books anything until you press the button. A meeting already in your diary that is part of the work can be counted towards it.
• It keeps checking. Radar reads each block back from the calendar: one moved past the deadline or deleted stops counting, and says why. Afterwards it asks whether you did it, and clearing the job gives back the time still booked for it.

Which calendars it counts

Runway needs a connected calendar. Without one, Radar can only show how many days are left. It counts every calendar you connect:

Calendar	How Radar uses it
Microsoft 365 and Outlook.com calendar	Read by Radar
Google Calendar	Read by Radar
A published calendar feed (ICS)	Read by Radar

Hiding a calendar from the calendar screen does not remove it from runway: a meeting you would rather not look at still takes the hour.

Who else does this

Comparing the effort a job needs with the time available is an old idea. Capacity planning in project tools has always done it. Calendar planners such as Motion and Reclaim go a step further and schedule the work into your diary for you. Radar does something narrower: it measures whether the time exists before the deadline, for everything you are carrying, and tells you weeks ahead when it does not. It does not move anything.

Written by Joel Lister · 25 Sep 2026