You can work out phases of the moon for any date from 1800 to almost 200 years into the future at this site: Click here. You will notice at the site that the times are either various US timezones, or UTC, which you may as well say is the same as GMT (Greenwich Mean Time). So always use UTC and add 12 hours to get the right result.

It was no surprise at all, having used this site, to find that the barque Stirlingshire was launched on a full moon, when there were two very high tides, one at day break and the other at dusk.