Tool
Deployment Time Picker
Pick a deploy window that minimises user impact across your customer geography and respects each on-call engineer's local night.
What makes this different
Two details set this apart:
- Weighted impact: 1am in Tokyo is not the same as 1am in Berlin for impact — weights per city capture this.
- On-call awareness: a "quiet" window with no engineer awake is worse than a slightly busier window with a responder on call. The tool ranks by impact subject to "at least one on-call engineer awake".
How to use it
- Add the cities your users live in, with rough weights.
- Add the cities your on-call engineers live in.
- Pick the target day (default: tomorrow).
- Read the recommended deploy window and the runner-ups.
"Deploy on a Tuesday" is the clich茅; the real question is: what hour of the week has the fewest users online across your geographies and at least one engineer awake to respond? This tool combines user-coverage data (assumed from typical waking-hour patterns per city) with on-call engineer timezones, and surfaces the lowest-impact UTC window.
Frequently asked questions
Where does the user-traffic weighting come from?
You provide it. The tool does not have access to your analytics. Enter rough weights based on where you know your customers are.
What if no time has an on-call engineer awake?
The tool will fall back to the time with the lowest impact among the engineers who would be reachable within 30 minutes of waking (i.e. late evening in their timezone).
Is Tuesday really the best day?
Statistically, yes — Tuesday and Wednesday carry the lowest aggregate deploy-failure rate in most published retrospectives. But the question is which hour, not which day.