🕒 dayjs-time-window

A lightweight Dayjs-based utility for handling daily time windows.
You can easily:

• Parse time strings (HH:mm:ss → Dayjs on current date)
• Build a same-day start–end window
• Check if a current time is within that window

📦 Installation

This package requires dayjs as a peer dependency.

npm install dayjs-time-window dayjs
# or
yarn add dayjs-time-window dayjs

🚀 Usage

1. Parsing a Time into Today (parseToday)

Converts "HH:mm:ss" to a Dayjs object on today's date, zeroing milliseconds.

import dayjs from "dayjs";
import { parseToday } from "dayjs-time-window";

const now = dayjs(); // current timestamp
const t = parseToday(now, "14:30:00");

console.log(t?.format("YYYY-MM-DD HH:mm:ss"));
// → 2025-11-24 14:30:00 (example)

2. Building a Time Window (buildWindow)

Creates start/end time points for today.

import { buildWindow } from "dayjs-time-window";

const { start, end } = buildWindow("09:00:00", "17:00:00");

console.log(start?.format(), end?.format());
// → start and end boundaries as Dayjs instances

3. Validating Whether Time Is Inside the Window (inWindow)

Checks whether a given time is between start <= now <= end.

import dayjs from "dayjs";
import { inWindow, buildWindow } from "dayjs-time-window";

const current = dayjs();
const { start, end } = buildWindow("10:00:00", "18:00:00");

if (inWindow(current, start, end)) {
  console.log("🟢 Open");
} else {
  console.log("🔴 Closed");
}

📚 API Reference

parseToday(now, hhmmss?)

Parses "HH:mm:ss" into Dayjs of today.

| Param | Type | Description | | -------- | ------ | ------------------------------------ | | now | Dayjs | Reference date (calendar day source) | | hhmmss | string | Time string (seconds optional) |

Returns: Dayjs | null

buildWindow(start?, end?)

Creates a start–end daily boundary using the current date from dayjs().

| Param | Type | Description | | ------- | ------ | ------------ | | start | string | "HH:mm:ss" | | end | string | "HH:mm:ss" |

Returns:

{
  start: Dayjs | null;
  end: Dayjs | null;
}

inWindow(now, start, end)

Checks if now falls between start and end inclusively.

| Param | Type | Description | | ------- | ------------- | ----------------------- | | now | Dayjs | Target time to validate | | start | Dayjs | null | Window start | | end | Dayjs | null | Window end |

Returns: boolean

🔧 Internal Logic Summary

• Times are parsed into today’s date (parseToday)
• Time windows are always current-day based (buildWindow)
• Milliseconds are stripped to avoid comparison mismatch
• Window logic is inclusive (start ≤ now ≤ end)

📄 License

MIT