I need the antonym of delay - name of the period before early arrival/departure and the scheduled one.

A bus that arrives five minutes late has five minutes of delay.

A bus that departs five minutes ahead of schedule has 5 minutes of (what?)

Note, it's not about surplus when you have saved up extra five minutes, but about a violation of schedule, when you arrive to the stop on time and can only shake your fist at the bus vanishing in the distance.

Technical or scientific, formal terms are most welcome although common are acceptable too.

  • There's probably no word for this because it happens so rarely that people have never needed to create a word for it. :-)
    – Hellion
    Feb 3, 2014 at 16:45
  • I suspect the best word to use will depend on context somewhat. How will this word be used?
    – phenry
    Feb 3, 2014 at 16:56
  • I probably wouldn't say a bus that arrives five minute slate has five minutes of delay, either. It sounds weird to me. I'd say it is delayed by five minutes, or a delay that is five minutes long. The time is a modifier of delay, not necessarily a commodity that can be owned by delay.
    – TylerH
    Feb 3, 2014 at 17:03
  • early arrival is possible, but the context you desire probably doesn't exist in a single word yet. Feb 3, 2014 at 17:04
  • In the UK, the Transport Commissioners regulate timetable adherence quite strictly (Bus firm First fined £285k by transport watchdog after one in four services run late.). For most purposes, running even 1 minute early is considered at least as bad as running 5 minutes late, for obvious reasons. I worked in that industry for decades, but I don't recall anyone using a noun for "early running time" corresponding to delay for late running. Feb 3, 2014 at 17:31

2 Answers 2


Given your need for a single word for UX purposes, as explained in your comment, I suggest ahead or early as your best options. Your goal is to provide information that will be understood quickly, with a minimum of additional information. While someone might come up with a word that's better as a true antonym of delay, it doesn't do you much good if the intended audience needs to be told what it means.

For a very pertinent example of this principle in action, see this tool, where a bus can have a 5 min delay or can be 5 mins early.


Common Usage

“[running] ahead [of schedule]” is the usual usage.

  • That bus is five minutes ahead.
  • That bus is five minutes ahead of schedule.
  • That bus is running five minutes ahead.
  • That bus is running five minutes ahead of schedule.

I don't believe there's a common noun for this meaning, however.

One might refer to that as being “hasty,” or “rushed”

  • That bus was hasty by five minutes.
  • That bus was rushed by five minutes.

Neither is a noun in the same structure as you requested, though, and the connotations are bit different:

  • “hasty” implies that an early departure was due to carelessness, or perhaps foolishness
    • it may be more familiar to speakers in the UK* and the American South and perhaps Midwest; I believe its usage is considered archaic or quaint in the Northeast and West;
    • *edit: It seems that this may not be colloquial in the UK, either; this usage might be limited to the US South. It's also a bit unusual to attribute a specific time interval to hastiness; it's generally used as an non-quantified attribute (“The bus's departure was hasty” or “the bus departed hastily” more often)
  • “rushed” implies external events conspired to force the early departure, which is a bit more similar to “delay”


“Premature“ also suggests itself, but still, not a noun.

A premature departure might imply that the bus's departure caused difficulty to someone more than “hasty” or “rushed,” but it does sound a bit formal.

Technical Usage

In technical terms, I would expect to see “advance” used as a noun, when time is understood:

  • The timing pulses arrived with 10ms delay
  • The timing pulses arrived with 20ms advance

… although it requires a context to understand that the “advance” is a time interval.

This is sometimes used in electronics/communications jargon.

This is similar to the usage of “timing advance” by automobile mechanics, but in that case refers to the timing as a relative position of the crankshaft rather than a time-unit (the actual time-interval this represents dependant upon the rotation speed of the engine)

  • The timing has a 5° advance

I wouldn't expect to see it in use in regards to transit, however:

✗ The bus departed with 5 minutes of advance

… seems very awkward

  • I have not heard “hasty” being used in that context, in the UK. Where did you get that from?
    – Tristan r
    Feb 3, 2014 at 17:47
  • 1
    Sorry, that was based more on a general impression than much of experience. I'll note it as such in the answer; it may be only a “Southern'ism” then.
    – BRPocock
    Feb 3, 2014 at 19:40

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