Tutorial 4 of 8
A renewal calendar for certificates and domains
Beginner 5 min
Collect TLS certificate end dates, expiring names from Certificate Transparency and domain registration expiry, and export them as an .ics calendar with reminders.
Expired certificates and lapsed domain registrations are among the most avoidable outages. Signalhouse turns three checks into one calendar:
| Check | Date it provides |
|---|---|
| DNS & certificate | end date of the certificate the site serves right now |
| Certificate history | names in Certificate Transparency logs whose newest certificate ends soon (subdomains too) |
| Domain history | registration expiry from RDAP |
1. Run the renewal checks
Open the template Certificate & renewal calendar, or add your own domains and include the three checks in the suite. If a project has no dates yet, the Renewals view (key 6) offers Run the renewal checks, which runs just these three.
Certificate Transparency data comes from crt.sh, which is sometimes overloaded. A failed check shows the reason (“crt.sh did not answer …”); use Retry failed in the progress strip or the run details a minute later.
2. Read the timeline
The timeline covers the next twelve months: circles are certificates, small circles certificates of subdomains, diamonds domain registrations and the triangle the next scheduled run. The table below lists every date with in N days, coloured amber inside your warning window and red once a date has passed.
Warn within (days) sets the warning window (also used for the scorecard colours). It is 30 days by default.
3. Download the calendar
Enter up to four reminder offsets in Reminders (days before) — for example 30, 7 — and press Download calendar (.ics). Each date becomes an all-day event with one alarm per offset; import the file into Google Calendar, Outlook or Apple Calendar.
The calendar is a snapshot: after a renewal, run the checks again and download a fresh file. With Re-run reminder set, the calendar also reminds you when the next run is due. SVG, PNG and CSV export the timeline and the dates for reports.
Ready to try it?