Weekday Parsing

Tempo provides a flexible way to parse Weekday inputs, allowing you to specify dates relative to the current day or a specific base date. This is particularly useful for phrases like "next Monday" or "3 Wednesdays ago".

Supported Formats

Weekday inputs typically consist of a modifier (optional), a count (optional), and the Weekday name.

1. Simple Weekday Names

You can provide the short or full name of a Weekday.

• Mon, Monday
• Wed, Wednesday
• Sun, Sunday

2. Symbolic Modifiers

Symbols can be used to indicate relative weeks or specific directions in time.
When no modifier is provided, Tempo defaults to the Weekday in the current week.

Modifier	Meaning	Example	Results in...
+	Next week	+Mon	Monday of next week
-	Previous week	-Tue	Tuesday of last week
<=	Prior to	<=Wed	The Wednesday immediately preceding (or equal to) today
<	Prior to (strict)	<Thu	The Thursday strictly before today
>=	Subsequent to	>=Fri	The Friday immediately following (or equal to) today
>	Subsequent to (strict)	>Sat	The Saturday strictly after today

Strict vs Inclusive Boundaries

The difference between < (strict) and <= (inclusive) is only relevant when you evaluate a string on the exact same weekday you are targeting.

For example, if today is Wednesday:

new Tempo('<Wed')  // → returns LAST Wednesday (strictly before today)
new Tempo('<=Wed') // → returns TODAY (inclusive match)

3. Keyword Modifiers

Keywords can be used for more natural language-like inputs.

Keyword	Meaning	Example
this	Current week	this Wed
next	Next week	next Monday
prev	Previous week	prev Fri
last	Last week	last Sunday

4. Count Modifiers

You can specify a number of weeks to jump by adding a count after the modifier.

• -3 Wed: Three Wednesdays ago
• +2 Mon: Two Mondays from now

5. Relative Suffixes

You can also specify the direction of time using a suffix.

• 3 Wed ago: Three Wednesdays ago
• 2 Mon hence: Two Mondays hence
• 2 Mon from now: Two Mondays from now

Time Suffixes

You can append time information to a Weekday string. Tempo will parse the Weekday first and then apply the time to that specific date.

• Mon 10:00am
• >Friday noon
• <3 Wed 15:30:00

How it Works

1. Normalization: Weekday names are normalized to their 3-letter proper-case prefix (e.g., monday -> Mon).
2. Anchor: If no time-zone or base date is provided, Tempo uses "now" as the anchor.
3. Calculation: The modifier and count determine the number of weeks to add or subtract from the anchor date to find the target Weekday.
4. Constraint: If time components are provided, they are set on the calculated date. Otherwise, the time defaults to 00:00:00 if it's the first parsing pass.