What direction should 12 oclock face on a sundial?
Sundials should always be positioned so that 12 is due north (towards the noth pole, not magnetic north). This will mean that the shadow will always indicate 12 o’clock precisely at noon GMT (UK winter time). All sundials are traditionally set to be accurate for GMT because ‘summer time’ did not exist when most of the ones on public buildings were intalled – GMT was in use the whole year round. Sundials are not traditionally adjusted for ‘summer’ and ‘winter’ time. Your sundial will read exactly one hour “slow” during the summer. The best way of aligning it accurately to True North during the summer is to wait until exactly 12 o’clock noon (as indicated by the pips on the BBC Radio 4) and then turning it so that the shadow of the gnomon points to 11. Then you will have an accurate sun dial which is correctly telling you true GMT (good ole’ British time). Don’t adjust it for winter time because it will be spot-on already. You need a clear day so that the sun’s shadow is sharp.
