Zmanim Calendar Generator Supports 2007 DST Changes

Sunrise CalendarThe Java version on the server was just updated to JDK 5.0 Update 11 and now supports the US 2007 DST Changes mentioned in the previous post. This means that Excel zmanim calendars generated by this site will have the proper daylight savings time for zmanim.

Zmanim Calendar Generator Does Not Yet Support 2007 DST Changes

Sunrise CalendarAs you may know, the U.S. is changing the Daylight Saving Time rules this year due to the Energy Policy Act of 2005. The server currently hosting this site does not yet have the Java patch for this. This means that from the second Sunday in March (the 11th) until the last Sunday in March (the 25th), calendars generated from the Zmanim Calendar Generator will show the zmanim in standard time and not daylight savings time (DST). The same issue will happen in the fall from the last Sunday in October (the 28th) till the first Sunday in November (the 4th). The Java version used by the server should be patched within the next week or 2 to the latest Java 5 (JDK 1.5) version to solve this problem.

Elevation Lookup Added to Zmanim Calendar Generator

Sunrise CalendarA lookup tool for elevation lookup was added to the Zmanim Calendar Generator page. This service is courtesy of Jonathan Stott’s earthtools.org elevation webservice. This Elevation data currently only covers all of mainland Europe (between latitudes 35°N and 60°N and longitudes 35°E and 15°W) and all of the contiguous states of the United States of America (between latitudes 20°N and 50°N and longitudes 65°W and 125°W). The source of the data is:

The terrain model used to find heights above sealevel is from the Shuttle Radar Topography Mission (SRTM) which was a joint project between the US National Geospatial-Intelligence Agency (NGA) and the National Aeronautics and Space Administration (NASA). Data was recorded for 11 days from the Space Shuttle Endevour from 11th February 2000. The data used here is at a resolution of 3 arc seconds (approximately 90m).

The lookup is done via an AJAX call.

Java Zmanim API Update


The first phase of change to allow easier porting to other languages took place with the change in the API from using inheritance of the Java Calendar classes, to one that uses composition. This will make porting it to other languages easier. Included in the update are a number of new zmanim, mostly the addition of a number of new calculations for plag that are useful when trying to avoid a tartai desasri with early erev shabbos minyanim.

Zmanim Calendar Generator Now using Google Maps

Vintage Map with CompassThe Zmanim Calendar Generator now has a simple way to look up longitude and latitude information using the Google Maps API. To use this feature, click on the Google Maps icon to display the map (location centered on Bais Medrash Gevoha in Lakewood), find the location that you want to generate zmanim for, and click that point in the map. This will update the longitude and latitude fields in the form. The Google API was pretty straight forward and simple. At the same time I tried to integrate an elevation lookup. Google does not provide elevation information, but I attempted to look it up using a webservice. This seemingly simple task was not very straight forward. The approach was to grab the SOAP response from the REST style elevation webservice made available by Jonathan Stott. My plan was to do this all via the client sided XML parsing. The first issue encountered was browser security that does not allow cross-domain loading of XML documents (By the way this was not using XMLHttpRequest, but the same security restrictions apply). This was solved by a simple PHP page that was just a proxy for the call. That done, I managed to get it to work in IE, but it crashed the browser every second call or so. The crashing was solved by adding a small delay. I never managed to get it working in Mozilla. I later tried to use the existing Google Maps API to load it, but never got it working. I commented out all elevation code, and will get to that part at some future date. I also removed the non decimal longitude and latitude option. I hope this will be useful.