Recurrence documentation for 'every April and December on the 1st and 24th' seems misleading

[claremacrae]

This arose out of discussion #610.

Expected Behavior

The docs in https://schemar.github.io/obsidian-tasks/getting-started/recurring-tasks/ contain this:

🔁 every April and December on the 1st and 24th (meaning every April 1st and December 24th)

I therefore expected to get this, after multiple completions - i.e. due dates being only April 1st and December 24th:

- [ ] Do stuff 🔁 every April and December on the 1st and 24th 📅 2025-04-01
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-12-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-04-01 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-12-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-04-01 ✅ 2022-04-20

Current Behavior

This is what I actually got - i.e. due dates being only April 1st and 24th, and December 1st and 24th

- [ ] Do stuff 🔁 every April and December on the 1st and 24th 📅 2025-04-01
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-12-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-12-01 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-04-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2024-04-01 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-12-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-12-01 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-04-24 ✅ 2022-04-20
- [x] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-04-01 ✅ 2022-04-20

Steps to Reproduce

Create this task:

- [ ] Do stuff 🔁 every April and December on the 1st and 24th 📅 2023-04-01

Then complete it multiple times.

Context (Environment)

• Obsidian version: 0.14.6
• Tasks version: 1.5.1
• [x] I have tried it with all other plugins disabled and the error still occurs

Possible Solution

Establish what the intended behaviour is, and then either update the docs or adjust the bug to indicate that the behaviour needs fixing.

[schemar]

Thanks, @claremacrae!

[claremacrae]

I do think that the actual behaviour is logical - and lean towards adding a test case for this, and updating the documentation to match the behaviour.

It makes it possible to add some quite powerful quarterly tasks, for example....

[claremacrae]

Fixed and published.