The problem
Events calendars on WordPress tend to get slower as they fill up. A local news site, a venue or a community group can list hundreds of events a month, and every repeating event multiplies the work a calendar page has to do. We wanted to see how far that could be pushed down, so we measured it.
There were two easy answers, and neither was good. Pay for a bigger server and keep going. Or move to another plugin and spend a weekend re-entering events, losing old links and search rankings along the way.
What we built
An events calendar for WordPress that does the common jobs well and keeps out of the way:
- Repeats stored once. Every date of a repeating event goes into a small indexed table when the event is saved. A month page reads the rows it shows and nothing else, instead of working out repeats on every view.
- Ordinary WordPress posts. Events keep revisions, featured images, comments, sitemaps and SEO plugins. Nothing custom to learn, and nothing to export if you leave.
- One plain editing box. Date, time, cost, venue, organiser, status, and a repeat rule written as a sentence: "Every week on Tuesday and Thursday, 10 times".
- A switch with a way back. Calendar² takes over existing events in place, keeping their IDs and addresses. A dry run reports what will move. A private preview shows the result on your own site. After the switch, a roll-back window (30 days by default) lets you hand everything back to The Events Calendar.
It's clean-room work: we built the switch from The Events Calendar's public documentation and the data on a test site, not from its source code.
The numbers
From our own tests in October 2026:
- 1,000 events migrated in 26 seconds (version 1.0.0).
- At 10,000 events: 4 to 8 minutes to prepare in the background while the site kept running, 13 seconds to switch and 7 seconds to roll back. With no edits in between, the roll-back gave back every original post exactly as it was.
- On a 10,000-event test calendar (17 Oct, a build from the day before 1.0.0, no page cache), Calendar²'s busiest month built in 90 ms against The Events Calendar's 197 ms, and the page was 22 KB gzipped against 553 KB. The views haven't been re-measured on 1.0.0 or 1.1.0 yet. Calendar² didn't win everything: its iCal feed is larger, and the performance page lists where else it lost.
These are our measurements on our test servers, not an independent benchmark. The method is on the performance page.
Where it is now
Calendar² 1.1.0 is on sale. The free plugin is the whole calendar, and it was submitted to WordPress.org for review on 18 October 2026. Calendar² Pro adds public event submissions with an approval queue and scheduled imports from other calendars, as a yearly licence from $79. We sell licences, not a cut of anything a site sells, and Pro keeps working if a licence lapses. Tickets², Give², Security² and Links² follow, on the same terms.
Why it's on this site
We build software for businesses. Calendar² is the same work, done for ourselves: find what's slow, measure it, fix the cause, and make sure leaving is as easy as arriving. If a system you depend on has outgrown itself, that's the work we do for clients, from £4,000, fixed price.