Timezone Utility

A versatile timezone management package with zero dependencies, designed for CommonJS, ES Module (ESM), JavaScript, and TypeScript projects. It offers a range of features, including timezone listing, retrieving labels and values, region-based filtering, and converting between UTC and other timezones.

Table of Contents

• ⚙️ Installation
• 📖 Usage
  • 📦 Importing the Package
  • 🌍 Get All Timezones (Label-Value Pair)
  • 🕑 et All Timezone Values (Without Label)
  • 🏷️ Get All Timezone Labels (Without Value)
  • 🌐 Get Timezones by Region
  • 🔖 Get Timezone Label from Value
  • 🎯 Get Timezone Value from Label
  • 🌏 Get List of Regions
  • ⏰ Convert UTC Time to Specific Timezone
  • 🔄 Convert Datetime From One Timezone to Another
  • 🌐🕓 Convert any Date-Time String to UTC Format
  • 🕰️ Get the Current Date-Time in a Specific Timezone
  • ➕➖ Add or Subtract Time (hours, minutes, or days) From a Date
  • 🕒➡️🕕 Get the Time Difference Between Two Timezones
• 📋 Methods Overview
• 📜 License
• 🤝 Contributing

Installation

Install the package using npm:

npm install timezone-utility

Usage

// For ES Module (ESM)
import { TimeZone } from "timezone-utility";

// For CommonJS
const { TimeZone } = require("timezone-utility");

1. Get All Timezones (Label-Value Pair)

Retrieve a list of all available timezones with both label and value.

const allTimezones = TimeZone.list();
console.log(allTimezones);

Output Example:

[
  { "label": "(UTC+00:00) Africa/Abidjan", "value": "Africa/Abidjan" },
  { "label": "(UTC-05:00) America/New_York", "value": "America/New_York" },
  ...
]

2. Get All Timezone Values (Without Label)

Get a list of timezone values (useful for APIs or forms where only the value is needed).

const timezoneValues = TimeZone.listWithoutLabel();
console.log(timezoneValues);

Output Example:

[
  "Africa/Abidjan",
  "America/New_York",
  ...
]

3. Get All Timezone Labels (Without Value)

Retrieve a list of timezone labels.

const timezoneLabels = TimeZone.listWithoutValue();
console.log(timezoneLabels);

Output Example:

[
  "(UTC+00:00) Africa/Abidjan",
  "(UTC-05:00) America/New_York",
  ...
]

4. Get Timezones by Region

Retrieve timezones for a specific region (e.g., America, Europe, Asia).

const americanTimezones = TimeZone.listByRegion("America");
console.log(americanTimezones);

Output Example:

[
  { "label": "(UTC-05:00) America/New_York", "value": "America/New_York" },
  { "label": "(UTC-06:00) America/Chicago", "value": "America/Chicago" },
  ...
]

Parameters:

• region: string: The region to filter by (e.g., "America", "Europe").

5. Get Timezone Label from Value

Retrieve the label (human-readable name) for a given timezone value.

const labelFromValue = TimeZone.getLabelFromValue("America/New_York");
console.log(labelFromValue);

Output Example:

"(UTC-05:00) America/New_York"

Parameters:

• value: string: The timezone value to convert to a label.

6. Get Timezone Value from Label

Retrieve the timezone value from a label.

const valueFromLabel = TimeZone.getValueFromLabel("(UTC-05:00) America/New_York");
console.log(valueFromLabel);

Output Example:

"America/New_York"

Parameters:

• label: string: The timezone label to convert to a value.

7. Get List of Regions

Retrieve a list of all available regions.

const regions = TimeZone.getRegions();
console.log(regions);

Output Example:

[
  "Africa",
  "America",
  "Asia",
  "Atlantic",
  "Australia",
  "Europe",
  "Indian",
  "Pacific"
]

8. Convert UTC Time to Specific Timezone

Convert a UTC/GMT time to a specific timezone and format it in either 12-hour or 24-hour format. You can also specify a custom date separator. By default, the function uses a 24-hour format (is24Hour = true) and the date separator is /.

const utcDate = "2024-10-15T14:00:00Z";
const convertedTime = TimeZone.convertUTCToTimeZone(utcDate, 'America/New_York', {is24Hour: false, dateSeparator: '/', timeSeparator: ':'});
console.log(convertedTime);

Output Example:

"10/15/2024, 10:00:00 AM"

Parameters:

• dateTimeString: string: The date-time string to convert.
• toTimeZone: TimeZoneNames: The target timezone.
• options: ConvertOptions (optional): Object containing optional formatting options:
  • is24Hour: boolean: Whether to use 24-hour format (default true).
  • dateSeparator: string: The date separator (default /).
  • timeSeparator: string: The time separator (default :).

9. Convert Datetime From One Timezone to Another

Convert a datetime from one timezone to another and format it in either 12-hour or 24-hour format. You can also specify a custom date separator. By default, the function uses a 24-hour format (is24Hour = true) and the date separator is /.

const originalDate = "2024-10-15T14:00:00Z";
const convertedTime = TimeZone.convertBetweenTimeZones(originalDate, 'America/New_York', 'Asia/Dhaka', {is24Hour: false, dateSeparator: '/', timeSeparator: ':'});
console.log(convertedTime); 

Output Example:

"10/15/2024, 12:00:00"

Parameters:

• dateTimeString: string: The date-time string to convert.
• fromTimeZone: TimeZoneNames: The source timezone.
• toTimeZone: TimeZoneNames: The target timezone.
• options: ConvertOptions (optional): Object containing optional formatting options:
  • is24Hour: boolean: Whether to use 24-hour format (default true).
  • dateSeparator: string: The date separator (default /).
  • timeSeparator: string: The time separator (default :).

10. Convert any Date-Time String to UTC Format.

Converts any date-time string into a UTC format (ISO 8601). This method also validates the input and provides a clear error message if the date is invalid.

const utcDate1 = TimeZone.convertToUTC('October 15, 2024 12:34:56');
console.log(utcDate1); 

const utcDate2 = TimeZone.convertToUTC('2024-10-15T12:34:56');
console.log(utcDate2); 

Output Example:

"2024-10-15T12:34:56.000Z"
"2024-10-15T12:34:56.000Z"

Parameters:

• dateTimeString: string: The date-time string to convert to UTC.
• format: string: The format of the date-time string (e.g., 'MM-dd-yyyy HH:mm:ss AM/PM', 'yyyy-MM-ddTHH:mm:ss').

11. Get the Current Date-Time in a Specific Timezone

Returns the current date and time in the specified timezone. The method allows formatting options such as 24-hour or 12-hour format and custom date and time separators.

const currentTimeInNY = TimeZone.getCurrentTimeInTimeZone('America/New_York', { is24Hour: false, dateSeparator: '-', timeSeparator: ':' });
console.log(currentTimeInNY); 

Output Example:

"10-15-2024 08:34:56 AM"

Parameters:

• targetTimeZone: TimeZoneNames: The target timezone in which you want the current time.
• options: ConvertOptions (optional): Object containing optional formatting options:
  • is24Hour: boolean: Whether to use 24-hour format (default true).
  • dateSeparator: string: The date separator (default /).
  • timeSeparator: string: The time separator (default :).

12. Add or Subtract Time (hours, minutes, or days) From a Date.

Adds or subtracts time (hours, minutes, or days) to a given date and returns the resulting date in UTC format.

const newDate = TimeZone.addTimeToDate('2024-10-15T12:00:00', 3, 'hours');
console.log(newDate); 

Output Example:

"2024-10-15T15:00:00.000Z"

Parameters:

• date: Date | string: The base date (as a Date object or string) from which to add/subtract time.
• amount: number: The amount of time to add (positive) or subtract (negative).
• unit: 'hours' | 'minutes' | 'days': The unit of time to add or subtract.

13. Get the Time Difference Between Two Timezones.

Calculates the time difference between two timezones in hours and minutes for a specific date.

const timeDiff = TimeZone.getTimeDifferenceBetweenTimeZones('2024-10-15T12:00:00', 'America/New_York', 'Asia/Tokyo');
console.log(timeDiff); 

Output Example:

"+13 hours 0 minutes"

Parameters:

• date: string: The base date-time string to calculate the difference from.
• fromTimeZone: TimeZoneNames: The source timezone.
• toTimeZone: TimeZoneNames: The target timezone.

Methods Overview

Method Name	Description
TimeZone.list()	Get a list of all timezones (label-value pairs).
TimeZone.listWithoutLabel()	Get a list of all timezone values.
TimeZone.listWithoutValue()	Get a list of all timezone labels.
TimeZone.listByRegion(region)	Get timezones by a specific region (e.g., "America", "Europe").
TimeZone.getLabelFromValue(value)	Get the timezone label for a specific value.
TimeZone.getValueFromLabel(label)	Get the timezone value for a specific label.
TimeZone.getRegions()	Get a list of all regions.
TimeZone.convertUTCToTimeZone()	Convert a UTC date/time string to a specific timezone, with support for 12-hour or 24-hour format (default 24-hour) and customizable date and time separators.
TimeZone.convertBetweenTimeZones()	Convert a date from one timezone to another with support for 12-hour or 24-hour format (default 24-hour) and customizable date and time separators.
TimeZone.convertToUTC()	Convert any date-time string into a UTC format (ISO 8601).
TimeZone.getCurrentTimeInTimeZone()	Get the current date and time in a specific timezone, with options for 12-hour or 24-hour format (default 24-hour) and customizable date and time separators.
TimeZone.addTimeToDate()	Add or subtract time (hours, minutes, or days) from a given date and return the result in UTC format.
TimeZone.getTimeDifferenceBetweenTimeZones()	Get the time difference between two timezones in hours and minutes for a specific date.

License

This project is licensed under the MIT License.

Contributing

We welcome contributions to this package! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request.

Key Points:

• The README.md provides clear instructions for installation, usage, and examples for each method.
• Each method is documented with a brief description, input/output, and examples.
• The convertUTCToTimeZone method now includes an option for the 12-hour/24-hour format, as requested.