Duration Calculation

Ignition
1

I have a simple parameter on a report called duration, and is calculated as follows:

fromMillis({EndDate}-{StartDate})

I get the correct time difference + 2 hours, it’s always exactly two hours more than what it should be. Why would this happen? The only thing I can think of is that my timezone is GMT+2, but that doesn’t make sense either

Any help? I don’t want to just subtract 2 hours to make it work.

I’ve also tried various date formatting options, all the same result

2

Sounds like one of the parameters is incorrect. Try showing both in the report and see which one you need to take a closer look at.

3

I actually did that, the timestamps are fine, I wonder if it's not maybe the fromMillis() instruction not factoring in the timezone, or something like that, the documentation states:

Creates a date object given a time, in milliseconds, past Unix epoch (1 January 1970 at midnight UTC).

4

It is factoring in time zone when you use fromMillis. I’d suggest scripting the duration.

Untested, but should get you close.

def hms(millisIn):
	seconds, ms = divmod(millisIn, 1000)
	minutes, seconds = divmod(seconds, 60)
	hours, minutes = divmod(minutes, 60)
	if hours > 24:
		days,hours = divmod(hours, 24)
		return '{}:{:02d}:{:02d}:{:02d}'.format(days,hours,minutes,seconds)
	else:
		return '{}:{:02d}:{:02d}'.format(hours,minutes,seconds)


startDate = data['StartDate']
endDate   = data['EndDate']

duration = endDate.getTime() - startDate.getTime()

data['duration'] =  hms(duration)
5

Use fromMillis() on each timestamp separately, and subtract them.

Like so:

fromMillis({EndDate})-fromMillis({StartDate})

fromMillis only works on dates/timestamps, not intervals.

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6

I appreciate the help, I will give it a go first thing tomorrow morning

7

I ended up going with this expression to get the time accurate and displayed correctly

dateFormat(fromMillis({EndDate}) - fromMillis({StartDate}) - fromMillis(getTimezoneRawOffset()*3600000),"HH:mm:ss")

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