SNAP ! - the sundial app - is available as a free web app, or as a
subscription app with many added features.
The free app displays a standard sundial face, and invites you to choose
from a list of countries and then of cities within that country. It
then displays the shadow of the gnomon (in daylight hours) appropriate
to that place and the current time. Also displayed is a blue line
indicating the exact solar time, and a red line indicating the exact
clock time at that location. These are also given in digital format at
the foot of the page.
The subscription app gives a wider choice of cities, and an alternative
to enter the latitude and longitude of any location. It also allows you
to select the current time or various times before and after it.
The dialplate display is the same as the free app, with the shadow and
the blue and red lines, but it also has an auto-refresh feature, and
there is much more information given at the foot of the page.
The make-up of clock time is given showing the values of Universal Time,
Timezone Offset, and Daylight Saving to give clock time, and the value
of the longitude offset and the Equation of Time to give solar time. In
addition, the following values are also given:
Apparent declination
Apparent altitude
Azimuth
Time of sunrise
Time of solar noon
Time of sunset
The subscription app costs $US11.99 for 1 year, or $24.99 for three
years. Purchasers of the subscription app have access to a forum in
which they can discuss their reactions and offer any suggestions they
may have for ongoing development in the future.
SNAP ! - the sundial app - is a joint development between Relative Data
Inc. of Ottawa, Canada and sundials.co.uk of Epsom, England. It can be
accessed from www.relativedata.com or www.sundials.co.uk
We hope that SNAP ! - the sundial app - will appeal to many members of
the sundial community, including sundial designers and makers, and that
they will find it useful in helping people to understand the mysteries
of the differences between sun time and clock time.
And we also hope that it will be of help in schools and other
educational institutions in encouraging an interest in sundials
generally.
--
Piers Nicholson
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