Webreport data inconsistancy

I have a webreport that detects Relays that haven’t reported in with the last hour. Lately, it has been fireing often, even though the Relays are reporting in. The report is using the inspectors “bes properties…” rather than just “last report time”, (which I can change). But I don’t understand why the time result would be different depending on which inspector method was used ? I know the time zones are different, but that shouldn’t effect the minutes being different.

Any ideas?

(now, last report time of it, (value of results (bes properties whose (name of it = "Last Report Time"),it)as string | "Missing")) of bes computers whose (name of it as lowercase = "xxxx")

( Fri, 23 Sep 2016 12:12:18 -0500 ), ( Fri, 23 Sep 2016 09:49:04 -0500 ), ( Fri, 23 Sep 2016 14:48:47 +0000 )