Hi,
When leaving on a very early trip, what is the earliest time one may put on tefillin and daven Shacharit?
Also, is it better to say Krias Shema as early as possible on one’s own, or to wait and say it later with a minyan, provided it is still within the zman?
1. Earliest time for Tefillin and Shacharit
The Shulchan Aruch (Orach Chaim 30:1) says:
זמן הנחתן בבוקר משיראה את חבירו הרגיל עמו קצת ברחוק ארבע אמות ויכירנו
The earliest regular time for tefillin is when there is enough daylight to recognize someone you are somewhat familiar with from a distance of four amos.
Regarding Shacharit, the Shulchan Aruch (Orach Chaim 89:1) says:
זמן תפלת השחר מצותה שיתחיל עם הנץ החמה … ואם התפלל משעלה עמוד השחר והאיר פני המזרח יצא
Ideally, one begins the Amidah at sunrise (netz hachamah). However, if one prayed after alot hashachar, once the eastern sky has become light, the prayer is valid.
For the actual times in your location, I highly recommend [MyZmanim.com](https://www.myzmanim.com). They’ve worked very hard to provide an amazing service.
2. Kriyat Shema — early or with a minyan?
My recommendation is to say Kriyat Shema as soon as its proper time arrives, at least the first pasuk, Shema Yisrael, followed by Baruch Shem Kevod Malchuto Le’olam Va’ed. Just in case you miss the Zman later.
Then, when you daven later, you’ll naturally say Kriyat Shema again as part of the regular prayers. There’s no need to make a complicated issue out of it.
As for davening with a minyan versus davening at home, people are different. For some, davening with a minyan is better. Others may find that they daven better at home, with more concentration.
Every person should understand what works best for them and choose accordingly.
Thank you