Date & Time Functions

Formula Pro custom functions for date arithmetic, formatting, and time calculations.

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ADD_DAYS

Adds a specified number of days to a date. Returns a date string in YYYY-MM-DD format.

Syntax: ADD_DAYS(date, days)

Parameter	Type	Description
date	Date, string, or number	The starting date
days	number	Number of days to add (use negative to subtract)

Example:

ADD_DAYS("2025-03-09", 14)

Result: "2025-03-23"

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SUBTRACT_DAYS

Subtracts a specified number of days from a date. Returns YYYY-MM-DD.

Syntax: SUBTRACT_DAYS(date, days)

Example:

SUBTRACT_DAYS("2025-03-23", 14)

Result: "2025-03-09"

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DATE_ARITHMETIC

Adds or subtracts days from a date. Same as ADD_DAYS/SUBTRACT_DAYS; use negative days to subtract.

Syntax: DATE_ARITHMETIC(date, days)

Example:

DATE_ARITHMETIC("2025-01-15", -7)

Result: "2025-01-08"

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ADD_MINUTES

Adds minutes to a datetime string. Accepts YYYY-MM-DD HH:mm:ss or YYYY-MM-DD. Returns ISO 8601 UTC string.

Syntax: ADD_MINUTES(date, minutes)

Example:

ADD_MINUTES("2025-06-27 07:00:00", 90)

Result: "2025-06-27T08:30:00.000Z" (or equivalent ISO string)

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SUBTRACT_MINUTES

Subtracts minutes from a datetime string.

Syntax: SUBTRACT_MINUTES(date, minutes)

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DATE_MIN / MIN_DATE

Returns the earliest date from multiple date arguments. Accepts date strings, numbers (timestamps), or timeline strings (YYYY-MM-DD+YYYY-MM-DD).

Syntax: DATE_MIN(date1, date2, ...) or MIN_DATE(...)

Example:

DATE_MIN("2025-03-01", "2025-03-15", "2025-02-20")

Result: "2025-02-20"

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DATE_MAX / MAX_DATE

Returns the latest date from multiple date arguments.

Syntax: DATE_MAX(date1, date2, ...) or MAX_DATE(...)

Example:

DATE_MAX("2025-03-01", "2025-03-15", "2025-02-20")

Result: "2025-03-15"

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WORKDAYS

Calculates the number of working days (Mon–Fri) between two dates.

Syntax: WORKDAYS(toDate, fromDate, [allowNegative])

Parameter	Description
toDate	End date (YYYY-MM-DD)
fromDate	Start date (YYYY-MM-DD)
allowNegative	Optional. "TRUE" or true to allow negative results; default is false (returns 0 if negative)

Example:

WORKDAYS("2025-03-14", "2025-03-09")

Result: 4 (Mon 9th to Fri 14th = 4 weekdays)

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FORMAT_DATE

Formats a date using Moment.js format tokens. Default format is "MMM DD, YYYY".

Syntax: FORMAT_DATE(dateInput, [formatString])

Common format tokens: YYYY (year), MM (month), DD (day), HH (hour), mm (minute), ss (second)

Example:

FORMAT_DATE("2025-03-09", "MMM DD, YYYY")

Result: "Mar 09, 2025"

Example:

FORMAT_DATE("2025-03-09", "YYYY-MM-DD")

Result: "2025-03-09"

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TIMEVALUE

Converts a time string to a decimal fraction of a day (Excel-compatible). Supports HH:MM, HH:MM:SS, and AM/PM formats.

Syntax: TIMEVALUE(time_text)

Example:

TIMEVALUE("09:00")

Result: 0.375 (9 AM = 9/24 of a day)

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HOURS_DIFF

Calculates the difference between two time strings in HH:MM format. Supports hours beyond 24.

Syntax: HOURS_DIFF(time1, time2)

Example:

HOURS_DIFF("18:00", "09:00")

Result: "09:00" (9 hours difference)

Example:

HOURS_DIFF("09:00", "18:00")

Result: "-09:00"