OpenTimezone

OpenTimezone is an open source, free, public API that converts time between different time zones.

OpenTimezone provides:

• A free, public API at api.opentimezone.com.
• Documentation at opentimezone.com.
• Self-hosting support (see the Installation section).

Usage

Example 1: Convert time from New York to London.

 curl -X 'POST' \
    'https://api.opentimezone.com/convert' \
    -H 'Content-Type: application/json' \
    -d '{
    "dateTime": "2024-10-14T00:00:00.000",
    "fromTimezone": "America/New_York",
    "toTimezone": "Europe/London"
    }' 

---

Example 2: Convert UTC to New York time.

curl -X 'POST' \
  'https://api.opentimezone.com/convert' \
  -H 'Content-Type: application/json' \
  -d '{
    "dateTime": "2025-09-17T04:36:48.131338",
    "fromTimezone": "UTC",
    "toTimezone": "America/New_York"
  }'

---

Example 3: Convert New York to UTC time.

curl -X 'POST' \
  'https://api.opentimezone.com/convert' \
  -H 'Content-Type: application/json' \
  -d '{
    "dateTime": "2025-09-17T00:36:48.131394",
    "fromTimezone": "America/New_York",
    "toTimezone": "UTC"
  }'

---

Example 4: List all supported time zones.

curl -X 'GET' 'https://api.opentimezone.com/timezones'

---

Installation

Option 1: Using Docker (recommended for self-hosting)

Requirements

• Docker.

How to Run

1. From the root folder of the project, run the following commands:

   docker build -t opentimezone -f ./src/Timezone.WebApi/Dockerfile .
   docker run -it -p 5280:8080 opentimezone

2. The API can be accessed at http://localhost:5280.

Option 2: Using Visual Studio (recommended for development purposes)

Requirements

• Visual Studio 2026.
  • With ASP.NET and web development installed from the Visual Studio Installer.
• Docker.
• .NET 10 SDK.

How to Run

1. Open the solution in Visual Studio 2026.
2. Run it using Docker.
3. The API can be accessed at https://localhost:5281.

How to Test

1. Open the solution in Visual Studio 2026.
2. Run the tests in Test Explorer.

Contributing

Pull requests are accepted.

License

MIT.