Today's Shacharit time isn't the same as it was a week ago, and it won't be the same next week either. Why? Because prayer times aren't based on a regular clock — they're based on the sun's path across the sky, and that changes every single day of the year, and at every latitude. To understand why your digital screen needs to know exactly where your synagogue is located, and why the times differ between Ashkenazi and Sephardi communities, it helps to understand the halachic logic behind it. In this article we'll walk through the principles.
Introduction to the "Seasonal Hour"
The first thing people struggle to understand: the "hour" in halacha isn't 60 minutes. In the language of the sages, a sha'ah ("hour") is a proportional part of the day — the day is divided into 12 equal parts, and each part is called a "sha'ah zmanit" (a seasonal, or halachic, hour).
A numerical example: on a day when the sun rises at 6:00 AM and sets at 7:00 PM, the total length of the day is 13 astronomical hours = 780 minutes. A seasonal hour = 780 ÷ 12 = 65 minutes. In other words, "three hours before midday" means 3 × 65 = 195 minutes, or roughly three and a half hours of regular clock time.
In summer, when the day is long, a seasonal hour is longer than 60 minutes. In winter, when the day is short, a seasonal hour is shorter than 60 minutes. That's why prayer times shift every week — not because of a "glitch," but because of this calculation.
Shacharit (Morning Prayer) Times
Shacharit times are the most tightly packed, and have the most differing opinions. Here are the main ones:
Alot HaShachar (Dawn)
The time the first light appears on the horizon. According to the commonly accepted method, this is 72 astronomical minutes before sunrise (in Israel). There are also opinions of 90 minutes (a stringent Ashkenazi custom), and another method based on "16.1 degrees below the horizon." This is the earliest time for washing hands and for praying after the fact (bedieved).
Misheyakir
The time a person can recognize an acquaintance from a distance of four amot. The practical time to put on tefillin and a tallit. In Israel: approximately 40-45 minutes before sunrise.
Netz HaChamah (Sunrise)
The moment the edge of the sun becomes visible above the horizon. The preferred time for Shacharit ("Vatikin") is to begin the Amidah precisely at sunrise. Sephardi communities and many Chassidic communities regularly pray Vatikin.
Latest Time for Shema — The Magen Avraham vs. Gra Dispute
This is where the most significant practical difference lies:
- The Magen Avraham method — The day begins at dawn (alot hashachar) and ends at nightfall (tzeit hakochavim). The latest time for Shema falls at the end of the third seasonal hour from dawn.
- The Gra method (the Vilna Gaon) — The day begins at sunrise and ends at sunset. The latest time for Shema falls at the end of the third seasonal hour from sunrise.
The practical difference: the Magen Avraham method sets the deadline 12-25 minutes earlier. Most Ashkenazi communities follow the Magen Avraham method, and most Sephardi communities lean toward the Gra method — but this varies from community to community.
Latest Time for Tefillah
The end of the fourth seasonal hour is the latest time to begin Shacharit. Again, the same two methods apply.
Mincha (Afternoon Prayer) Times
Mincha is a more flexible prayer, but it too has distinct times:
- Chatzot HaYom (midday) — The midpoint between sunrise and sunset. The earliest time you can begin Mincha Gedolah.
- Mincha Gedolah — Chatzot plus half a seasonal hour. Most communities only allow Mincha to begin from this time.
- Mincha Ketanah — Nine and a half seasonal hours from the start of the day. The preferred time for Mincha, lechatchilah.
- Plag HaMincha — One and a quarter seasonal hours before the end of the day. The earliest time you can pray Maariv (under certain conditions). There's a dispute over whether to calculate it by the Gra method (sunrise to sunset) or the Magen Avraham method (dawn to nightfall).
Accurate prayer times — automatically, based on your location.
Beita calculates all the zmanim automatically based on your synagogue's location — including different cities, different halachic methods, and Shabbat times.
Learn about the digital screen Start 30 days freeMaariv (Evening Prayer) Times
Maariv is the only prayer whose time window stretches across the whole night:
- Shkiah (sunset) — The time the sun disappears below the horizon. For some poskim (halachic authorities), this is the earliest time for Maariv (if Mincha was prayed before plag hamincha).
- Tzeit HaKochavim (nightfall) — The time when three medium-sized stars become visible. The accepted time for Maariv, lechatchilah. In Israel: 13-25 minutes after sunset, depending on the season.
- Between sunset and nightfall — "Bein HaShmashot" — A complex halachic period. Some opinions hold that it's already night; others that it's still day. For the evening Shema, you must wait until nightfall.
Shabbat Times
Shabbat is even more challenging, because it involves the entry and exit of a prohibition on melacha (creative work):
- Candle lighting — According to the common custom in Israel: 18-20 minutes before sunset (in Jerusalem, 40 minutes, per local custom). In some Sephardi communities, sometimes even less.
- Sunset — The start of Shabbat, according to all opinions.
- Motzei Shabbat (end of Shabbat) — Here there are two main approaches:
- 42 minutes after sunset — A common method in Sephardi communities and some Ashkenazi ones.
- 72 minutes after sunset — Rabbeinu Tam's method, the custom of many stringent Ashkenazi communities.
If the synagogue publishes the end of Shabbat according to the 42-minute method, but part of the community follows the 72-minute method, it creates a sense of distrust. The solution: publish both times, or make sure the official time matches your target community.
Want to calculate it yourself?
Try our free zmanim calculator — enter a location and get all the halachic times of day, including Shabbat times, no sign-up required.
Go to the free zmanim calculator →Why It Matters for the Synagogue to Know Its Local Times
A common mistake is downloading a generic app and displaying its times on the digital screen. But prayer times vary significantly by location:
- Between northern and southern Israel, there's a 10-15 minute difference in sunrise and sunset.
- In mountain cities (Tzfat, Jerusalem), "star visibility" times differ from those at sea level.
- In communities abroad, the differences are even larger.
On top of that, the halachic method has to match the community. A Chabad synagogue will display different times than a Sephardi synagogue. An Ashkenazi-Litvish synagogue will prefer the Gra method, and a Chassidic synagogue will sometimes prefer the Baal HaTanya's method. A generic calculation will show the wrong number for part of the community.
A good digital screen for a synagogue must allow for three configurations: precise location (latitude/longitude), halachic method, and community custom for Shabbat times. Beita's digital screen calculates all of this automatically based on your synagogue's location. Read more about setting up prayer times in the system.
Prayer times aren't a technicality — they're the heart of the prayer service. When the community sees an accurate, clear time on the screen that matches their custom, it feels serious and trustworthy. When they see a generic number that doesn't match what they're used to, it creates doubt. Invest the time in setting up the times correctly from the start, and you'll save yourself questions all year long. And for edge cases — always consult a rabbi qualified to rule on halachic matters. See all of Beita's plans and pricing.