NYSE Holiday Half-Day Schedules Have No Fixed Rule

Summary

The document asks whether the NYSE follows a predictable calendar rule for closing early around Independence Day and Christmas. It describes apparent patterns inferred from historical dates, including early closes near July 4, and notes that an upcoming schedule did not fit the poster’s tentative interpretation. The question highlights why relying on a few historical examples may not be enough to build a reliable calendar rule.

The reply reports that an NYSE contact said there is no general policy determining half-day dates; the stated exception concerns the exchange being open for a full session on the year’s final day. This is a brief, secondhand answer rather than a formal exchange calendar specification. The practical takeaway is to use published schedules instead of assuming historical patterns will reliably predict future early closes. The document does not provide a complete holiday schedule or guidance on how an application should retrieve or maintain official calendar data.

Key ideas

• The historical timing of NYSE early closes does not establish a general scheduling rule.
• A brief report from an NYSE contact says half-day dates are not governed by a general policy.
• The reply identifies a full trading session on the final day of the year as an exception.
• Applications should not rely on inferred holiday patterns as a substitute for published schedules.

Tags

# NYSE Early Close Rules (July 4th and Dec. 25th)


# NYSE Early Close Rules (July 4th and Dec. 25th)












Does the NYSE provide a list of rules for determining when to close at 1:00 for a holiday? I have found a list of upcoming half-days here but I would like to know the rules so that I don't have to hard-code them in my application.

I found a list of all of the dates on which the NYSE closed early in its history here*. I could discern three rules for half-days that I would like to verify:





- July 4th: if July 4th is a Tues, Wed, or Fri, close at 1:00 on the previous day. If July 4th is a Thur, close at 1:00 on the next day.

The list of upcoming holidays shows that Wednesday, July 3, 2013 is a half-day. This conflicts with what looks like their previous policies. I'm guessing that in the future, July 5th will never be a half-day and that July 3rd will be a half-day if it falls on a Mon, Tues, Wed, or Thur (similar to the Dec 24th rule).

*According to that historic list I linked, the NYSE used to be open on Saturdays. I thought that was interesting.

## Answer by chrisaycock (score 2)

https://quant.stackexchange.com/a/7132

I emailed one of my contacts at NYSE, who replied that there is no rule or policy governing half days (other than that the exchange must be opened for a full day on the last day of the year).

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.