extendedDateToBasic — GTM Variable Template for Date

VARIABLES › DATE

extendedDateToBasic EXTENDED Date

Direct (.tpl) Apply (.tpl) Add to GTM

Converts an extended ISO date (YYYY-MM-DD) to basic format (YYYYMMDD).

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When to Use This

Date Formatting

Format and transform date values into human-readable or machine-readable strings.

Type Conversion

Safely convert between data types — strings, numbers, booleans, arrays, objects.

Date & Time

Calculate durations, differences, and time-based operations on date values.

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Examples

Extended to basic ISO date▶ Try

INPUT

Extended Date: 2024-12-25

OUTPUT

20241225

Invalid returns undefined▶ Try

INPUT

Extended Date: 2024-12-2

OUTPUT

undefined

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Live Sandbox

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

extendedDateToBasic

Read-Only Try Live

Extended Date

💾 The extended date string in "yyyy-mm-dd" format.

Supported formats:
  ✓ String

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the input before internal logic (e.g., convert object to string, normalize case). Internal transformations such as case handling will still apply afterward.

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.

Extended Date string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

extendedDateToBasic()

+ Chain another variable

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Related Variables

Same category: Date

→ addDays → basicDateToExtended → calculateDaysDifference → calculateLeadTime → currentTimestamp → dateToUnixTimestamp → daysToMilliseconds → getDayIndexFromDateString → getDayName → getDayNameFromDateString → getDayNameShort → getHourOfDay → getMonthName → getMonthNameShort → hoursToMilliseconds → isBusinessHours → isWeekend → millisecondsToDays → millisecondsToHours → millisecondsToMinutes → millisecondsToSeconds → minutesToMilliseconds → reverseDateCompactDay1st → reverseDateCompactYear1st → reverseDateSlash → secondsToMilliseconds → subtractDays → timestampToDayIndex → unixTimestampToDate

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Under the Hood

📜 View Implementation Code

/**
* Convert an extended ISO 8601 date string (yyyy-mm-dd) to basic ISO format (yyyymmdd).
*
* @param {string} data.src - The extended date string in "yyyy-mm-dd" format.
* @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
*
* Direct-mode specific parameters:
* @param {Function} [data.pre] - Optional pre-processor function to transform src before conversion.
*
* @returns {string|undefined} The date in "yyyymmdd" format, or undefined if the input is invalid.
*
* @framework ggLowCodeGTMKit
*/
const extendedDateToBasic = function(date) {
   if (typeof date !== 'string' || date.length !== 10) { return undefined; }
   return date.split('-').join('');
};

const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);

// ===============================================================================
// extendedDateToBasic - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(extendedDateToBasic(value));

// ===============================================================================
// extendedDateToBasic() – Apply Mode
// ===============================================================================
/*
return function(value) {
  return out(extendedDateToBasic(value));
};
*/

🧪 View Test Scenarios (5 tests)

✅ '[example] Extended to basic ISO date'
✅ Valid date with January first - converts correctly
✅ Valid date end of year - converts correctly
✅ '[example] Invalid returns undefined'
✅ Non-string input - returns undefined