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BMNT and EENT today: sun, moon and twilight times for where you stand

BMNT is nautical twilight starting in the morning, EENT is the same thing ending at night, both at the moment the sun crosses 12° below the horizon. FieldGrid's Sun & Moon screen pulls both for today at wherever your GPS says you're standing, alongside sunrise, sunset, every other twilight, moonrise, moonset and how lit up the moon is.

2 min read · Updated 2026-09-23

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What those two acronyms actually mean

BMNT is Begin Morning Nautical Twilight, EENT is End Evening Nautical Twilight. Between the two there's enough natural light to pick out shapes and a horizon line; outside them, dark enough that it counts as dark. Stand-to times, movement plans and night training all get built around these two numbers.

Twilight definitions used by FieldGrid
EventSun position
Astronomical twilight18° below the horizon
BMNT / EENT (nautical twilight)12° below the horizon
Civil twilight6° below the horizon
Sunrise / sunset0.833° below the horizon (upper edge of the sun)

Getting today's times on screen

  1. Get a GPS fix on the Map tab.
  2. Open Tactical tools and tap the row labeled "Sol & Luna" (yes, that label's still in Spanish; the screen it opens is titled Sun & Moon, in English).
  3. Under SUN, read Sunrise, Solar noon and Sunset, plus the sun's current direction and height.
  4. Under TWILIGHT, read Astronomical AM, BMNT (nautical AM), Civil AM, Civil PM, EENT (nautical PM) and Astronomical PM.
  5. Under MOON, read the phase, Illumination, Moonrise and Moonset. The screen refreshes every 30 seconds.

Example: one evening's full picture

FieldGrid at 37.74870, -119.58720 on 15 October 2026, phone set to Pacific time
EventTime
Astronomical AM05:39
BMNT (nautical AM)06:09
Civil AM06:40
Sunrise07:06
Solar noon12:48
Sunset18:29
Civil PM18:59
EENT (nautical PM)19:29
Astronomical PM19:59
Moonrise12:19
Moonset21:15
MoonWaxing crescent, 20% illumination

A thin 20%-lit moon staying up until 21:15 means the night doesn't actually go fully dark until well after sunset. Easy to miss if you're only glancing at EENT and not the moon line underneath it. The app's own short tactical notes at the bottom of the screen flag nights exactly like this one.

How much to trust these numbers

  • Today only, at your current GPS position, in your phone's time zone. There's no date picker, so tomorrow isn't something you can look up here.
  • Sun times run on a simplified solar model, good to within a few minutes. Moon times are rougher than that.
  • Hours and minutes, cut off rather than rounded, so don't read a trailing second as precision.
  • Needs a GPS fix, needs no signal, which is the entire reason it works in the field at all.

Questions and answers

Can FieldGrid show BMNT and EENT for tomorrow?
No, today only, wherever you happen to be standing. Open it on the actual day, or reach for an almanac for anything further out.
What is the difference between BMNT and civil twilight?
BMNT marks the sun at 12° below the horizon; civil twilight kicks in at 6°. In the worked example above, 31 minutes separate the two.
Does it need internet?
No, just your GPS position and the phone's own clock.
Why does the tools list say Sol & Luna?
That one row just hasn't been translated yet. It still opens the right Sun & Moon screen.

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