Hebcal Developer API minor updates

We’re pleased to share a couple of brief and minor updates to our collection of Developer APIs.

  1. We now recommend using HTTPS for all of our APIs. We’ve updated our documentation to reflect this. Most of our JSON APIs still support HTTP. Some of our APIs now return a 301 redirect from the HTTP version to the HTTPS version.
  2. We implemented some simplistic rate-limiting to throttle clients who are sending too many API queries. You may receive a 429 “Too Many Requests” error if your client makes more than 90 requests in a 10-second window. Remember, this is a free service; please be polite and send batch API requests slowly over a longer period of time.

First day of Chanukah on Christmas

As many have noted, the first day of Chanukah coincided with Christmas this year (December 25, 2016).

This happens approximately three times each century. Prior to this year, the most recent occurrence was in 1978, and the next time this will happen will be in 2027.

For completeness, here are the co-occurrences of the first day of Chanukah and Christmas during the past 400 years:

And here are the next two hundred years:

Users of hebcal for UNIX can verify this for themselves using a command like the following:

./hebcal --years 600 1617 | \
  grep 'Chanukah: 1 Candle' | \
  grep '^12/24' | \
  cut -c 7-10

Yom HaAliyah / יום העלייה

We’ve added a new modern holiday, Yom HaAliyah (יום העלייה). Yom HaAliyah recognizes Aliyah, immigration to the Jewish State of Israel.

More info from Wikipedia:

Yom HaAliyah (Aliyah Day) (Hebrew: יום העליה) is an Israeli national holiday celebrated annually on the seventh of the Hebrew month of Cheshvan, to commemorate the historic events which happened on the tenth of the Hebrew month of Nisan (Hebrew: י’ ניסן). The holiday was established to acknowledge Aliyah, immigration to the Jewish state, as a core value of the State of Israel, and honor the ongoing contributions of Olim to Israeli society.

The holiday was first observed on 7 Cheshvan 5777 (November 8, 2016).