Article of the month December

The Qibla

For the Moslem, not only the time for prayer is important; knowledge of the direction to Mecca is also necessary. This direction is called Qibla..
Islamic sundials frequently had a Qibla line, but one is possible on sundials anywhere.
The figure below shows a south dial for the Sonnenborgh observatory in Utrecht. The Qibla is shown in red.

To indicate the Qibla, the pole style gnomon has an index. It is square over the small cross in the drawing. The distance to the sundial face is equal to the line at the top of the sundial.

When the shadow of the index falls on the Qibla line, the sun is in the direction of Mecca.

South dial for Utrecht, with Qibla

There are many constructions and formulas to determine the Qibla. Today, the computer makes it even simpler.
Go to www.qiblalocator.com and navigate to the desired location. The example shows the Utrecht observatory.
You may select either a map or a satellite photo. In either case, the direction to Mecca is indicated both numerically, and by a red line.

Sonnenborgh Observatory, Utrecht, with the Qibla in red

On two days every year, it is possible to determine the Qibla directly from the position of the sun – if it happens to be out.
On those two days, the Mecca sun zeniths at local true noon.
In that instant, for everywhere else in the world, the sun is in the direction of Mecca.

The dates and times are:
27/28 May, 9:18 UTC
15/16 July,9:27 UTC

If necessary, remember to convert UTC to your local time.

Further information, in English, may be found on the Internet site of our member Robert van Gent.