Technology countdowns: 4 dates with a rule behind them
Release cadences and technology observances with a published schedule rule rather than an announced date. The next one is Patch Tuesday on Tuesday, 13 October 2026, 20 days from today.
What is coming up in technology?
| Event | Next date | Weekday | Days away |
|---|---|---|---|
| Patch Tuesday | 13 October 2026 | Tuesday | 20 |
| World Backup Day | 31 March 2027 | Wednesday | 189 |
| System Administrator Appreciation Day | 30 July 2027 | Friday | 310 |
| Programmers' Day | 13 September 2027 | Monday | 355 |
How are these technology dates worked out?
4 of the 4 entries here come from a written rule, which means a date can be produced for any year by evaluating it. Nothing in this category depends on an announcement, so every date on every page below can be produced years ahead. No keynote or conference is listed. Every major technology event picks its dates a few months ahead and announces them, which is an announcement rather than a rule.
The rule behind every technology date
| Event | Rule |
|---|---|
| Patch Tuesday | The second Tuesday of every month, the published cadence for Microsoft’s scheduled security updates. |
| World Backup Day | Fixed on 31 March, the day before April Fools’ Day. |
| Programmers' Day | The 256th day of the year, which is 13 September in an ordinary year and 12 September in a leap year. |
| System Administrator Appreciation Day | The last Friday in July, so it can land on any date from the 25th to the 31st. |
When in the year do these technology dates fall?
Counting this year and next, the 4 entries here fall across 12 of the twelve months: January (1), February (1), March (2), April (1), May (1), June (1), July (2), August (1), September (2), October (1), November (1), December (1). March is the busiest, carrying 2 of them. Technology has very few dates that survive contact with a countdown. Product launches slip, conferences move, and a keynote announced in March can be in a different week by May. What does hold is a release cadence. Microsoft ships scheduled security updates on the second Tuesday of the month and has done so consistently enough for the phrase to enter the language, which makes it the rare technology date that can be calculated rather than looked up. The rest of this category is observances, which are fixed by definition.
What is each of these technology events?
- Patch Tuesday
- The only entry in this catalogue that recurs monthly rather than yearly, so it has twelve dates a year instead of one.
- World Backup Day
- An awareness day rather than an industry event, which is why it has a fixed date and no venue.
- Programmers' Day
- 256 is the number of distinct values in one byte, and the highest power of two below 365. The leap day is the only thing that moves it.
- System Administrator Appreciation Day
- Observed in IT departments rather than by any government. The weekday rule has not changed since it was established.
Why does a rule matter more than a date?
A countdown is only worth publishing if the number on it is right, and a number is only right if the date under it is. A date copied from somewhere is correct until the year it is not, and nothing on the page will say when that happened. A rule fails differently: if the rule is wrong, every year is wrong at once and it shows up immediately. That is why this catalogue prefers a rule it can evaluate over a date it has to trust, and why events that only ever have an announced date are left out even when they are far more searched than the ones that made it in.
Every technology countdown
Other categories
Event countdowns · When is it? · Date calculator · Moon phases