Add Weekday — VSCode Extension

Automatically append Japanese (or English) day-of-week characters to dates in Markdown and plain text files.

Before:

ミーティング: 4/22
レビュー: 4/28
リリース: 2026/6/30

After:

ミーティング: 4/22(火)
レビュー: 4/28(月)
リリース: 2026/6/30(火)

Usage

Open a Markdown or plain text file
Open the Command Palette and run Add Weekday: 曜日を付与（上書きなし） / Add Weekday
- To re-tag dates that already have a weekday, run Add Weekday: 曜日を付与（上書き） / Overwrite Weekday

Works great with Obsidian vaults — Daily Notes, Meeting Notes, and TODO lists with mm/dd dates are converted quickly.

Setting	Default	Description
`addWeekday.format`	`paren-ja`	Output format: `paren-ja` → `4/20(月)`, `paren-en` → `4/20(Mon)`, etc.
`addWeekday.weekdayStyle`	`null`	Override weekday style (`ja` / `ja-full` / `en-short` / `en-long`)
`addWeekday.dateOrder`	`MDY`	How to read ambiguous dates: `MDY` (month/day) or `DMY` (day/month)
`addWeekday.yearMode`	`current`	Year inference: `current` / `next` / `nearest`
`addWeekday.overwrite`	`false`	Re-tag dates that already have a weekday
`addWeekday.mdOnly`	`false`	Skip `yyyy/mm/dd`; only tag `mm/dd`
`addWeekday.targetLanguages`	`["markdown","plaintext"]`	File types to activate for
`addWeekday.runOnSave`	`false`	Auto-convert on save
`addWeekday.showStatusBarItem`	`false`	Show a status bar button

If you prefer not to install from the Marketplace: