Date & Time Calculations

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Date & Time Calculations

DTO.SubtractMonths - Subtract Months from a Date

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MiniRobotLanguage (MRL)

 

DTO.SubtractMonths Command

Subtract Months from a Date

 

Intention

 

The DTO.SubtractMonths command (alias submon) is used for date calculations, specifically to subtract a given number of months from a date. The command correctly handles rolling back over year boundaries.

 

For example, subtracting 3 months from February 15, 2024, will correctly result in November 15, 2023. This is useful for calculating past dates, such as finding a warranty expiration date or a 3-month-prior notification date.

 

Syntax

 

DTO.SubtractMonths|date|months|[format]|[$$RES]

 

Parameter Explanation

 

date - The source date string (e.g., "15.02.2024") or a variable containing one.

months - The integer number of months to subtract from the date.

format - (Optional) The format mask for the input `date` and the resulting output date.

$$RES - (Optional) The variable to store the resulting date. If omitted, the source variable provided in `date` is updated.

 

Example

 

'**********************************************

' DTO.SubtractMonths - Sample

'**********************************************

'

' Set the starting date.

$$DAA = "15.02.2024"

' Define how many months to subtract.

$$NUM = 3

' Perform the subtraction and store the new date in $$RES.

DTO.SubtractMonths|$$DAA|$$NUM||$$RES

' Display the result.

MBX.Original: $$DAA | Result: $$RES

' Expected output: Original: 15.02.2024 | Result: 15.11.2023

ENR.

 

Remarks

 

If subtracting months results in an invalid day for the target month (e.g., subtracting 1 month from March 31st), the day is typically adjusted to the last valid day of that month (e.g., February 28th or 29th). This behavior is handled by the underlying date/time engine.

 

See also:

 

    DTO. - Date Time Operations

    DTO.Add Months

    DTO.Subtract Days

    DTO.Subtract Years

    DTO.Date Diff