The living may be easy, but telling the time isn’t. Summer began a couple of days ago, but the clocks changed to summer time just over a month ago. Except they didn’t: officially, we don’t have summer time. In 1968, Irish Standard Time was defined to be one hour ahead of GMT, and in 1971, winter time was defined to be the same as GMT. In practice, Irish time has mostly been the same as British time since the end of Summer Time in 1916 (the year it was introduced). Prior to that, the standard time across Ireland, as decreed in 1880, was Dublin Mean Time, which was 25 minutes and 21 seconds behind Greenwich Mean Time, with Dunsink Observatory as the reference point.
The clock on the North Range of the Royal Hospital is just over an hour slow, perhaps still showing winter time (almost). The building dates from 1684, long before the railways demanded the use of a standard time across the country, so the sundial should show local time. That would be roughly the same as Dublin Mean Time, with a small adjustment for the Equation of Time, or about an hour and 22 minutes behind standard time, all told. It doesn’t, and one source puts this down to a gross error made during one of two known restorations. So what time is it? Lunchtime.