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Supported Timezone Data Formats

ContactMonkey accepts timezone information in multiple formats to ensure compatibility with your existing data systems. This article explains which formats are supported and how the system handles timezone data.

How Timezone Data is Processed

ContactMonkey checks each recipient's timezone data in the format provided. The system does not attempt multiple data formats for a single recipient.

Supported Data Formats

ContactMonkey accepts timezone data in four formats, listed from most to least precise:

1. IANA Timezone (Recommended)

The IANA (Internet Assigned Numbers Authority) Timezone Database is the most accurate format for timezone information. It accounts for regional variations, daylight saving time rules, and historical timezone changes.

Format: Region/City

Examples:

  • America/Toronto
  • Europe/London
  • Asia/Tokyo
  • Australia/Sydney

Why it's recommended: IANA timezones provide the most precise timezone data and automatically handle daylight saving time transitions.

View complete IANA timezone reference table

2. GeoNames Database

GeoNames is a geographical database that provides timezone information based on location identifiers.

Required fields:

  • geoname_id (e.g., 5128581 for New York City)

Optional supporting fields:

  • country_name (e.g., United States)
  • country_code (e.g., US)
  • city_name (e.g., New York City)
  • subdivision_1_iso_code (e.g., US-NY-MN)
  • subdivision_2_iso_code (e.g., US-NY)

3. Postal Code

ContactMonkey can determine timezone based on postal or zip codes from supported countries.

Format: Standard postal code format for the recipient's country

Examples:

  • United States: 10001
  • United Kingdom: SW1A 0AA
  • Canada: M5V 2H1
  • Australia: 2000
  • Japan: 197-0001

Note: For best results, combine postal codes with country information.

4. Country

ContactMonkey accepts multiple country name formats, including ISO standards and common variations.

Supported formats:

  • ISO Long Name (e.g., "The United States of America")
  • ISO Short Name (e.g., "United States of America")
  • Alpha-2 Code (e.g., "US")
  • Alpha-3 Code (e.g., "USA")
  • Common name (e.g., "United States")

Examples:

ISO Long Name ISO Short Name Alpha-2 Alpha-3
The United States of America United States of America US USA
Canada Canada CA CAN
The United Kingdom of Great Britain and Northern Ireland United Kingdom of Great Britain and Northern Ireland GB GBR
The United Mexican States Mexico MX MEX

Limitation: Country-level timezone data is the least precise format and may not accurately represent recipients in countries with multiple timezones.

What Happens with Invalid Data

If all of a recipient's timezone data is:

  • Missing
  • Incorrectly formatted
  • In an unrecognized format

Result: The email will be sent to that recipient at the scheduled time in your timezone (the sender's timezone).

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