Candle lighting times

Contents

• When does Shabbat begin?
• What is Havdalah (or, When does Shabbat end)?
• If I use 72 minutes for Havdalah, why are Havdalah times ~90 minutes later than the previous day's candle-lighting time?
• How accurate are candle lighting times?
• How are candle lighting times determined from my zip code?
• What cities outside of the USA are available?
• How can I look up candle-lighting times for any city in the world?
• What are the Daylight Saving Time options?

When does Shabbat begin? [#shabbat]

Shabbat begins 18 minutes before sundown on Friday night. In Jerusalem, Shabbat begins 40 minutes before sundown.

What is Havdalah (or, When does Shabbat end)? [#havdalah]

Shabbat ends after sundown on Saturday night when there are three stars visible. Depending on latitude and longitude, this is usually between 42 and 72 minutes after sundown.

If I use 72 minutes for Havdalah, why are Havdalah times ~90 minutes later than the previous day's candle-lighting time? [#mismatch]

Shabbat begins 18 minutes before sundown on Friday night.

Havdalah is 72 minutes after sundown on Saturday night.

So in a given week, Havdalah time is typically 90 minutes after the previous day's candle-lighting time (18 + 72 = 90). Sometimes there's an extra minute or two difference, and that's due to sunset actually differing by a minute or two between Friday and Saturday nights.

How accurate are candle lighting times? [#accurate]

Hebcal computes sunset based on an algorithm provided by the U.S. Naval Observatory (USNO). The USNO claims accuracy within 2 minutes except at extreme northern or southern latitudes. Comparison to local NWS charts for sunrise and sunset (which are cheap and easy to come by) shows that with the double precision calculations, the charts produced by this program are no more than 1 minute removed from those charts in lattitudes lower than 41 degrees. Candle lighting times agree with those on popular calendars also to the 1 minute accuracy.

That said, the USNO algorithm can only approximate the candle-lighting times for your location. If you ever have any doubts about Hebcal's times, consult your local halachic authority.

How are candle lighting times determined from my zip code? [#zip2geo]

Since candle lighting times are determined from latitude and longitude, a process called geocoding is used to determine the geographic position of a zip code. Your zip code is looked up in a geocoded database of about 42,000 zip codes (1999 ZIP Code data from the U.S. Census Bureau's Gazetteer project).

The Gazetteer data from 1999 is much more complete than their data from 1990 -- but still not as good as the commercial-quality data you get from the U.S. Post Office. Gazetteer contains zip code, city name, latitude and lognitude but is missing time zone.

Fortunately, the Gazetteer data contain a FIPS code (which represents the county a zipcode is part of). The U.S. National Weather Service provides county-timezone data (keyed on FIPS code), which contains timezone and Daylight Saving Time data for each county. By joining these two data sources, we can get a complete picture of each zip code.

What cities outside of the USA are available? [#cities]

For a list of the 47 international cities supported by hebcal.com, see the Hebcal Cities page. This page also includes latitude, longitude, and time zone.

How can I look up candle-lighting times for any city in the world? [#geo]

Example: how to find candle-lighting times for San Jose, Costa Rica.

1. Go to the Getty Thesaurus of Geographic Names at http://www.getty.edu/research/tools/vocabulary/tgn/
2. Type "San Jose" in the Find box and click "Search" button
3. Click on the link that says "San Jose, Costa Rica, inhabited place"
4. Note the latitude/longitude represented in "degrees minutes direction" (in the example of San Jose, Costa Rica it is Lat: 09 56 N and Long: 084 05 W) and write this information down on a sheet of paper
5. Go to the Hebcal Interactive Jewish Calendar at http://www.hebcal.com/hebcal/
6. In the "Candle lighting times" section, click on the link that says "select by latitude/longitude"
7. Type the latitude and longitude into the form (9 degrees, 56 minutes North Latitude, 84 degrees 5 minutes West Longitude)
8. Select the Time zone and Daylight Saving Time options specific to your location
9. Click "Get Calendar" button at the bottom of the form

What are the Daylight Saving Time options? [#dst]

Hebcal offers 6 options for DST:

USA and Canada

begins at 2 a.m. on the second Sunday of March

ends at 2 a.m. on the first Sunday in November

Mexico

begins at 2 a.m. on the first Sunday of April.

ends at 2 a.m. on the last Sunday of October.

European Union

begins at 1 a.m. on the last Sunday in March

ends at 1 a.m. on the last Sunday in October

Australia and New Zeland

begins at 1 a.m. on the last Sunday in October

ends at 1 a.m. on the last Sunday in March

Israel

begins at 2 a.m. on the last Friday before April 2nd

ends on the Sunday Selichot begins

None

hebcal makes no adjustments for summer time

To learn more about Daylight Saving Time in general, read Daylight Saving Time from webexhibits.org.