
In function 'formatDatetime' the value provided for date time string (of 24:00:00) was not valid. datetime string must match ISO 8601 format. Since when is 24:00:00 not ISO 8601 format? My Flow has worked for months, and suddenly fails when 24:00:00 is used. Is that not what comes after 23.59:59? Is there no 24:00:00, requiring 00:00:00 to be used instead?
It would not surprise me if 2400 was not excepted. Technically, yes, 2400 is acceptable, but only in theory, because even a nanosecond past the strike of midnight is consider 0000. Hope this helps.
Here is an excerpt from the following link:
"Most electronics that track time use the 0000 notation."