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Trail terms

Nero day

Also called nero, near-o, near-zero day

What is a nero day?

A nero day, short for nearly zero, is a day on a long trail when you hike only a few miles and spend the rest of it resting or doing town chores. It sits between a full hiking day and a zero day, when you hike no miles at all.

Nero day at a glance

Short for
Nearly zero
Official cutoff
None
Rule of thumb
25% or less of your daily average
Halfway Anywhere's PCT glossary
Zero day
No trail miles at all

How many miles is a nero?

There is no official number. Backpacker magazine defines a nero as an almost rest day where you hike nearly zero miles. Halfway Anywhere's Pacific Crest Trail glossary says there is no official cutoff and puts it at usually 25 percent or less of your daily average.

By that measure, a hiker who averages 20 miles a day would call anything up to about five a nero. The public radio language show A Way with Words has described it more loosely, as a day of a mere ten miles or so. It is slang, and the working definition is a day short enough that most of it happens off the trail.

Why take a nero instead of a zero?

Because it gets most of the rest and all of the chores while the trip still moves forward. The usual pattern is to camp a few miles short of a road, walk into town early, and have most of a day for food, laundry, a shower and the resupply. The mirror image is a slow morning in town and a few miles out to the first campsite.

It is also cheaper. A full zero generally means sleeping in town on both sides of it, and a nero in and a nero out can cover the same errands on one night's lodging, or on none.

What does a nero change about your pack?

Nothing directly. A nero is a line in the schedule and you cannot buy one. What matters to the pack is the spacing of town stops that neros and zeros happen at, since that spacing sets how many days of food you carry out each time.

Stops that are close together mean short carries and a small pack. A long stretch between them means several more pounds of food and a pack with the volume and frame to carry it.

What this means when you're choosing

  • Pack volume and load rating sized for your longest stretch between town stops
  • Campsites a few miles short of a road crossing, which is what makes a nero into town possible
  • A written chore list for town, so that a half day covers what a full one would

Nero day vs Zero day

Nero dayZero day
Trail milesA fewNone
Forward progressSomeNone
Time off your feetMost of a dayA full day
Nights in townOne, or noneUsually two

Which to pick: Take a nero for chores and a breather, and a zero when your body needs a whole day without the pack on.

The common mistake

Counting a nero as a full day of rest

A nero still means packing up, carrying a loaded pack and walking on the same feet. It works for errands and a mental reset. If you are stopping because something hurts and needs time off your feet, a nero will not give it that, and a zero will.

Common questions

What does nero stand for?

Nearly zero, or near zero. It comes from zero day, the long-trail term for a day with no miles hiked. A nero is the next thing up: a day with only a few.

How many miles is a nero day?

There is no fixed figure. Halfway Anywhere's Pacific Crest Trail glossary puts it at usually 25 percent or less of your daily average, which works out to about five miles for a hiker who averages 20 a day.

Is a nero better than a zero?

It depends what the day is for. A nero keeps the trip moving and usually costs one night in town where a zero costs two. A zero gives a full day off your feet, which a nero does not.

Where this is defined

Where this comes up

Guides on Tom's Hiking where nero day changes which product is right for you.

Going deeper

More in trail terms

Base weight

Base weight is everything in your pack except food, water and fuel: the gear that doesn't get used up. It's the number backpackers compare, because consumables vary with trip length while base weight is a property of your kit.

Ultralight

Ultralight is a style of backpacking built around a base weight under 10 lb. It gets there by making the big three lighter and by carrying fewer things, which trades comfort in camp and margin in bad conditions for comfort while walking.

Fastpacking

Fastpacking is covering a multi-day route with a pack light enough to run in, somewhere between trail running and ultralight backpacking. Typical loads run 8 to 20 liters, and the trip is usually run downhill and on the flat and hiked uphill.

Thru-hiking

Thru-hiking is walking a long trail end to end in one continuous trip, usually within a single season. The Appalachian Trail, Pacific Crest Trail and Continental Divide Trail are the best-known examples in the US, each taking several months.

Shoulder season

The shoulder seasons are spring and autumn, the months either side of settled summer conditions. Days can be warm and nights near freezing, weather changes faster, and gear that works in July is often not enough in late September.

Three-season

Three-season gear is built for spring, summer and autumn but not sustained winter conditions. It's the default rating for most backpacking equipment, and in practice it means handling rain, wind and light frost but not deep snow.

Layering system

A layering system is the practice of combining a moisture-moving base layer, an insulating mid layer and a protective shell, so you can regulate temperature by adding and removing pieces rather than relying on one heavy garment.

Zero day

A zero day is a day on a long trail where you walk no trail miles at all, usually taken in a town to rest, resupply and deal with logistics. A nero is a near-zero: a handful of miles into or out of town with the rest of the day off.

Cowboy camping

Cowboy camping is sleeping outside with no shelter over you: a pad, a bag or quilt, and the sky. It saves the weight and the time of pitching a tent, and it trades away protection from rain, wind, dew, insects and anything that walks past in the night.

Postholing

Postholing is breaking through soft snow with each step and sinking to your shin, knee or thigh, leaving a line of holes behind you. It is exhausting, it can drop your pace to under a mile an hour, and it damages the trail for everyone following.

Slickrock

Slickrock is bare, exposed sandstone with no soil on it and no tread cut into it. You walk on the rock itself and follow cairns rather than a path. Dry sandstone gives excellent grip; wet or dusty sandstone gives very little, which is where the name misleads people.

Trailhead

A trailhead is the designated access point where a trail begins, and usually where you park and start walking. Many have a map board, signs or a toilet. The US Forest Service draws a firm line: a plain junction of two trails, or of a trail and a road, is not a trailhead.

Treeline

Treeline is the elevation, or latitude, above which trees can no longer grow. It is less a line than a zone where trees shrink into stunted, wind-shaped growth, and it sits at very different heights: between 5,000 and 6,000 feet in Washington's Olympics, and above 10,000 in the Sierra.

Backcountry

Backcountry is undeveloped land away from roads and drive-in campgrounds, reached on foot or by water. In US parks it is the opposite of frontcountry, where you drive to a campground, and camping there often needs a permit. It is not the same as legally designated Wilderness.

Big three

The big three are a backpacker's shelter, sleep system and pack: the three items where most of a kit's weight sits and, as REI puts it, where you can cut the most. The usual advice is to lighten the shelter and sleep system first and choose the pack last.

Section hiking

Section hiking is completing a long trail in pieces, one stretch at a time over separate trips, rather than in one continuous push. The Appalachian Trail Conservancy counts anyone who finishes the whole trail in more than 12 months as a section hiker, and recognizes them as 2,000-milers alongside thru-hikers.

NOBO and SOBO

NOBO and SOBO are thru-hiker shorthand for northbound and southbound, the direction someone walks a long trail. On the Appalachian Trail a NOBO starts at Springer Mountain in Georgia and finishes at Katahdin in Maine, and a SOBO walks the same 2,000-plus miles the other way.

Slackpacking

Slackpacking is hiking a stretch of a long trail with only a daypack while someone else moves the rest of your gear, usually a shuttle that drops you at one road crossing and collects you at the next. You still walk every mile; you just sleep indoors and carry less.

Naismith's rule

Naismith's rule estimates how long a hike will take: one hour for every three miles of distance, plus one hour for every 2,000 feet of climbing. A Scottish mountaineer wrote it in 1892 for fit walkers taking short halts, so most people need longer.

By Tom · Last reviewed . Back to the glossary