Resolve relative and natural language date expressions to concrete ISO dates. Use this skill whenever you need to compute a relative date like "next Wednesday", "3 fridays from now", "in 2 business days", or "end of month". Also use it for calendar lookups, day-of-week checks, and computing how far away a target date is (including business days). This skill handles the date *math* — the error-prone computation part. It does NOT handle knowing today's date (that should already be in your context via a hook or system prompt). Trigger on any date arithmetic: "when is", "how many days until", "what day of the week is", scheduling math, deadline computation, or any expression that needs resolving to a concrete date. Even if you think you can do the math yourself, use the script — off-by-one errors in date arithmetic are common and undermine trust.