Time Data Series: Working with PHP Zmanim

Acknowledgements

This post continues my exploration of concepts and techniques related to both the way so-called Jewish times (zmanim) are calculated; as well as the techniques needed to use thePHP Zmanim library a library of functions that let you easily calculate Jewish times. Once again I owe a huge debt of gratitude to several folks including Eliyahu Hershfeld, creator of theKosher Java library, Zachary Weixelbaum (owner of the PHP Zmanim library, a port of Kosher Java), Elyahu Jacobi (who builtRoyZmanim.comwith those tools and patiently explained so many concepts to me), and Maor Neim, who offered explanations that turned theory into practice.

Introduction

In my last postI explored both the foundational concepts of Jewish time calculations (zmanim) and also the initial steps needed to install and use PHP Zmanim. We got as far as calculating sunrise with that library.

By itself, this isnt particularly impressive. The fact is that, with the same information (latitude, longitude, time zone, and a specific date) you can get the same information using PHPs built-in functions.

In this post, were going to get into the types of calculations you CANT get with built-in PHP tools, not only because they require some interesting time manipulations, but because there are so many ways to calculate the same religiously significant moment, based on various Rabbinic opinions and traditions.

The Answer to Every Jewish Question Starts with Well, it depends

Let me take a minute to unpack that idea in a little more detail.

In the last post, I started to get into this idea:

Dawn is the moment when light (but not the sun) is visible over the horizon. Unfortunately, whether or not there is or isnt light is highly subjective, and therefore the way its come to be calculated ranges all over the map.

• Some traditions use a fixed number of clock minutes before sunrise or after sunset.
• Others will use astronomy to identify the time when the sun is below the horizon by a specific number of degrees.
• Others will use a formula, such as taking the amount of daylight (from sunrise to sunset), dividing that into 10 equal parts, and then subtracting that amount from sunrise or adding it to sunset.
• Still others will take the time the sun is below the horizon on an equal day (meaning the spring or fall equinox, when the amount of sunshine and darkness are exactly the same), calculate the difference (in clock minutes) between that time and sunrise, normalize those minutes against seasonal minutes (shaot zmaniyot) for the specific day in question, and finally subtract that amount from sunrise (or add THAT to sunset) for the day in question.

One moment of the day, but a wide variety of ways to determine it.

It may be hard for those outside of mainstream orthodox Judaism to understand, and is definitely the subject of a completely different type of blog post, but the answer is to embrace the understanding that all of the calculations above (and many others) are capital-T True. Not just in a well, its how I feel about it so its true to me kind of way, but as being absolutely, factually, empirically true even when one method stands in opposition to another (or several others).

Like I said, THAT is the topic of a completely different blog post.

For now, I mention this to explain why, in creating theKosher Java library, Eliyahu Hershfeld took the route of enabling the ability to easily calculate times using ANY of those methods, rather than trying to espouse a single method and coding exclusively for that. And ports such as Zachary WeixelbaumsPHP Zmanim library simply continue with that ideal.

Which brings us back to the nitty-gritty of using the PHP Zmanim library.

Making Time Pretty

In the last postwe left off with this snippet of code:

<?phprequire 'vendor/autoload.php';use PhpZmanim\Zmanim;use PhpZmanim\Calendar\ComplexZmanimCalendar;use PhpZmanim\Geo\GeoLocation;# Set variables:#41.4939407, -81.516709;$locname = "Beit Knesset Chochmat Shlomo, Beachwood, OH";$lat = 41.4939407;$long = -81.516709;$elev = 0;$tz = 'America/New_York';$getyear = 2024;$getday = 20;$getmonth = 12;$testzmanim = Zmanim::create($getyear, $getmonth, $getday, $locname, $lat, $long, $elev, $tz);$sunrise = $testzmanim->sunrise;echo "$sunrise
";?>

Which produced a result that looked something like this:

2024-12-20 07:48:52

It works, but its not what Id want to see on a page when Im just expecting a simple 7:48 am.

Which brings me to the next interesting insight for the PHP Zmanim library: You can format the output using another function, rather than hammering through PHPs built-in options. Youll still use thePHP time/date formatting codesbut getting what you want is easier.

Lets say I want to only display the hour, minute, and am/pm for the sunrise output. Id add a line like this:

$sunrise = $zmanim->sunrise;$sunrise = $sunrise->format('g:i a');

Which would look like this when printed to the screen:

7:48 am

Getting your first actual real time Mincha Gedola

The problem with using sunrise/sunset as an example is that PHP has built-in options to do the exact same thing. So lets look at getting a time that is more relevant to Jewish religious times: the earliest time for afternoon prayers (Mincha Gedola).

Once again, its somewhat anti-climactic in that its a single command:

$gedolah = $zmanim->minchaGedola;

Which outputs a time like this:

2024-12-20 12:46:55

HOWEVER, as I mentioned earlier in this post, there are several ways to calculate this time. Here are all the methods supported by the PHP Zmanim library:

• minchaGedola: Returns a time 6.5 halachic hours (shaos zmaniyos) after sunrise.
• minchaGedola30Minutes: Returns the time 30 standard (clock) minutes after the half-day calculation (chatzot).
• minchaGedola72Minutes: Calculates according to the Magen Avraham (Abraham Abele Gombiner, 1635-1682) with the day starting 72 minutes before sunrise and ending 72 minutes after sunset.
• minchaGedola16Point1Degrees: Calculated according to the Magen Avraham with the day starting and ending when the sun is 16.1 degrees below the horizon.
• minchaGedolaAhavatShalom: Calculated based on the opinion ofRabbi Yaakov Moshe Hillelas half a seasonal hour (shaah) after mid-day (chatzos) with seasonal minutes (shaos zmaniyos) calculated based on a day starting 72 minutes before sunrise and ending 13.5 minutes after sunset.
• minchaGedolaGreaterThan30: This is a convenience method that returns the later of the standard minchaGedola function or minchaGedola30Minutes. In the winter when 1/2 of a seasonal hour (shaah) is less than 30 minutes, then minchaGedola30Minutes will be returned, otherwise the regular minchaGedola will be returned.
• minchaGedolaAteretTorah: This method returns the time ofmincha ketanaaccording to the Magen Avraham with the day starting and ending when the sun is 16.1 degrees below the horizon.
• minchaGedolaBaalHatanya: This calculation is based on the opinion of theBaal Hatanya
• minchaGedolaBaalHatanyaGreaterThan30: This is a convenience method that returns the later of either minchaGedolaBaalHatanya or minchaGedola30Minutes. In the winter when 1/2 of a seasonal hour (shaah) is less than 30 minutes, then minchaGedola30Minutes will be returned, otherwise minchaGedolaBaalHatanya will be returned.
• minchaGedolaGRAFixedLocalChatzos30Minutes: This method returns a time based onRav Moshe Feinsteinsopinion.

As you can see, there are a number of opinions. Determining which one you want/need to use is outside the scope of this blog post, and will likely require some conversations with the users of the app or website, as well as a Rabbi. Or two. Or several.

But the good news is that to use any of them, its as simple as:

$gedolah = $zmanim->minchaGedola16Point1Degrees;$gedolah = $gedolah->format('g:i a');

Getting something complicated Nightfall (Tzais Hakochavim)

Now that youve seen how we get one time, you should understand that even times that my prvious post labeled as complicated arent that that complicated. Furthermore, it should reinforce your understanding of just how powerful a tool like PHP Zmanim is, because of what it enables you to do in such a short time.

Calculating nightfall (tzais hakochavim) is as simple as the command

$tzais = $zmanim->tzais;

If there is any challenge at all, its the sheer number of variations to consider. Im listing them here without explanation, just so you have a sense of how many there are. Thats right, there are 32 different options for calculating this one time. I list them here without detailed explanation simply to underscore my point:

• tzais
• tzais72
• tzaisGeonim3Point7Degrees
• tzaisGeonim3Point8Degrees
• tzaisGeonim5Point95Degrees
• tzaisGeonim3Point65Degrees
• tzaisGeonim3Point676Degrees
• tzaisGeonim4Point61Degrees
• tzaisGeonim4Point37Degrees
• tzaisGeonim5Point88Degrees
• tzaisGeonim4Point8Degrees
• tzaisGeonim6Point45Degrees
• tzaisGeonim7Point083Degrees
• tzaisGeonim7Point67Degrees
• tzaisGeonim8Point5Degrees
• tzaisGeonim9Point3Degrees
• tzaisGeonim9Point75Degrees
• tzais60
• tzaisAteretTorah
• tzais72Zmanis
• tzais90Zmanis
• tzais96Zmanis
• tzais90
• tzais120
• tzais120Zmanis
• tzais16Point1Degrees
• tzais26Degrees
• tzais18Degrees
• tzais19Point8Degrees
• tzais96
• tzaisBaalHatanya
• tzais50

Time (and this blog series) Marches On

Armed with the information in this post, you could probably make decent headway simply by looking through the main README on ZacharysPHP Zmanimpage itself, and selecting the best (for your purposes) calculations for:

• Sunrise and Sunset (no, do not singThat Song)
• A seasonal hour (Shaah Zmanim)
• Dawn (alos hashachar)
• The earliest time to put on tallit and tefillin (misheyakir)
• The latest time to say Shema (sof zman kria shema)
• The latest time for morning prayers (sof zman tefillah)
• When Passover begins
• Halfway through the day (chatzos)
• The earliest time for afternoon prayers (mincha gedola)
• The best time for afternoon prayers (mincha ketana)
• The latest time for afternoon prayers (plag hamincha)
• The time to light Shabbat candles
• Dusk the time between sunset and night (bain hashmashot)
• Night (tzais hakochavim)
• Halfway through the night (chatozs halayla)

But there is still more to cover. In upcoming articles Ill talk about:

• Taking these standard times and adjusting them for synagogue specific needs (Mincha starts 25 minutes before Shkia each day).
• Using the PHP Zmanim library to display non-time calculations such as the weekly Torah Portion, Rosh Chodesh, and the Molad.
• Leveraging the build-in astronomy functions for time calculations that arent built into the library itself.

I hope youll continue on this journey with me. As always if you have questions, comments, or kudos, please leave them in the comments.