Working with Power Automate: Calculate 30 Days Ago

This article is part of the Working with Power Automate series I am writing on my experiences working with the Power Automate, which is part of the Power Platform from Microsoft. I also have a related series of articles on Power Automate with Microsoft Dynamics 365 BC.

I was working on a flow a while ago and was using the Microsoft Dynamics 365 Business Central “Find record V3” action and needed to select invoices posted over 30 days ago. To do this I needed to calculate the date 30 days before the present date.

I did some digging and found the required function, which, somewhat counter-intuitively, is called addDays:

The function requires three parameters:

1. timestamp – date to base the calculation on; I used the function utcNow() to get current date/time.
2. days – the number of days to add or, if a negative number, the number of days to subtract
3. format – format for the date, which I always use the ISO date format for as this ensures that both UK and US date systens will correctly compare (UK uses dd-MM-yyyy whereas the US uses MM-dd-yyyy).

addDays(utcNow(), -30, 'yyyy-MM-dd')

The expression returns the current date minus 30 allowing me to use this in the filter to only selected invoices older than this date.