IsToday function is what I can a “nice to have” function, and I’m happy it exists. Although you could do the math yourself, having a function that tells you if your date/time belongs to the current day is fantastic. There are a lot of applications for this, but I think Microsoft included this one since Power Apps deal with a lot of customer-facing information, most of them filtered by the current day. If we needed to implement the calculations ourselves each time we wanted to filter something by the present day, it would be a mess of code.
So let’s look a bit at how the IsToday function works.
It follows a simple pattern.
- Date and time to compare
Let’s start with a basic example:
IsToday(Now()) will return true
It looks obvious but remembers that the Now function returns date and time. So calculating if the time fit’s on your definition of “today” depending on timezones and daylight savings is quite impressive.
Now let’s create the date with the “Date” function and see what we get:
IsToday(Date(2021,9,30)) will return true
Now let’s try with strings:
IsToday('2021-09-30') will return an error
Although the date is valid, we need to convert it first before using it. To do that, we’re using the DateTimeValue function.
IsToday(DateTimeValue("2021-09-30")) will return (today is the 30th of September 2021) true
It’s a limitation, in my opinion, but a reasonable restriction that the function only accepts “date/time” objects. Allowing other objects, like timestamps and strings, would make things a lot more complex. This way, the function can limit its domain to “checking if the date is today” instead of “convert if needed, check if it’s a date, and then check if the date is today”. It’s complex enough the do the checking correctly.
Don’t do the math
The whole point of the IsToday function is so that you don’t need to do the math. So, for example, you don’t need to parse the date and check if the day, month, and year is the same as the current date, the time is under the same timezone, and if not, convert it, etc.
It does all of this for you, so please use it.
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