I believe you heard a VOLMET station (from a French contraction for 'flying weather') which gives weather information for various waypoints. The 'zulu' time is a well known shorthand for GMT or UTC (for our purposes, functionally identical)
If you listened a while, you would have also heard New York on the air after Gander finished. I haven't listened for quite a few years; I remember New York Radio on for 40 minutes followed by Gander Radio for 20 minutes each hour.
Right. I hear Gander on 6604 and 3485 at night as well as 10051 during the day between :20 and :30 minutes past the hour and again at :50 to :00. New York Radio, when it's operational, takes the remaining time.