When I am asked to describe the Jewish tradition in strictly ritual or religious terms, I often say that the Jewish tradition is an all-encompassing one, offering moments for spiritual connection throughout the day.

In rabbinic parlance, zmanim—prayer times—play a large role in that. Of course, specific prayer times are not the only opportunities we have during the day for spiritual connection. Rather, zmanim are in place to offer structure to our days, reminding us to stop with intention and take time out for our practice.

What are zmanim?

Zmanim is the plural of the Hebrew word zman, meaning time or invitation. Zmanim most often refer to the specific windows of time during the day when particular prayers may be recited according to the traditional rabbinic understanding. Zmanim are also sometimes used in Jewish communities to refer to the times when holidays or Shabbat begin.

In order to understand how zmanim work, it’s important to know how the Jewish day works.

You may be familiar with the fact that the Jewish day begins at sunset. This is because in the first chapter of Bereshit/Genesis, we are told that there was evening and there was morning—one day. The six days of creation each begin with evening and the seventh day of rest—Shabbat—begins in the evening after the six days are completed (Genesis 2:1).

For the purposes of Jewish law and reciting particular prayers at their set times (most notably the Shma and Amidah), daylight hours are divided into twelve relative or seasonal hours. There are, as with so many things in Judaism, multiple opinions on the length of time that needs to be divided into these twelve hours. According to the Magen Avraham, the time between alot hashachar—dawn—and tzeit hakochavim—nightfall—is divided into twelve hours. According to the Vilna Gaon, the time between sunrise and nightfall is divided into twelve hours.

What is an hour according to this system?

We’re used to the idea that an hour is sixty minutes. We are so accustomed to this that we take it totally for granted and don’t give it a second thought.

However, time and how we keep track of it is arbitrary.

For the rabbis and for many Jews today, dividing the day into twelve hours made it much simpler to keep track of the precise time that the Shma and Amidah needed to be recited each morning. Similarly, it was helpful for knowing when Mincha—the afternoon prayer—could be recited.

Since the amount of daylight, we experience varies seasonally, so would the amount of time each day that a person would have to say the prayers at their proper time. This is why sha’ot or hours can be as short as 50 minutes in the winter and as long as 70 or 80 in the summer. An hour’s length is determined by calculating the length of time between dawn or sunrise and nightfall and dividing that number by 12.

Thank G-d, there is now an app for that! Many Jews who want to look up a zman just have to take out their phones and open the app.

This simple calculation was most helpful before we were able to rely upon regulated timekeeping.

Why does this matter?

It is entirely understandable to wonder why any of this matters. Isn’t this pedantic? Prayer is prayer.

Who cares when I recite it?

For many Conservative/Masorti Jews, chiyyuv—or obligation to do mitzvot daily at specific times—really matters spiritually and ritually. In addition to providing a structure for the day, these times offer us opportunities to step out of our routines and remember that we’re part of a tradition that has been in existence for thousands of years. When we take time out to do Jewish in this way, we’re taking our place in that chain.

Obligation? That sounds so constricting!

For Western folks like us, the idea of obligation carries with it a feeling of burden or trial. For many Jews, obligation is an opportunity to show up when it matters most. A case in point is being part of a minyan for someone who needs to say Kaddish.

Instead of a person running around franticly trying to get a minyan together at a random time, zmanim ensure that there are preset windows of time when each of the three daily prayers—Maariv, Shacharit, Mincha—is recited.

Think about how hard it is to schedule meetings with others. We’ve all been there—the endless Doodles and emails. When we set a regular time, we feel a sense of relief—or at least I know I do!—not wondering when the next meeting will be. So, too, prayer times provide a framework for our days, our weeks, months and years. This framework can allow us to live lives rich in meaning, structure and points of contact with our communities, the Divine and ourselves.