X-WR-CALNAME:Training
BEGIN:VEVENT
DTEND:20180426T171500
DTSTAMP:20180419T122646Z
DTSTART:20180426T163000
SEQUENCE:0
The above format is very common and results in the time being relative to Z also on the DTEND and DTSTART because no local timezone is specified nor can be derived from the ical file. Time formats are described in this post: https://stackoverflow.com/questions/10518804/formatting-time-for-ical-export
http://unicode.org/cldr/charts/32/supplemental/zone_tzid.html