Log in or register
Share on LinkedInShare on LinkedIn

ARTICLE · 07 MAY 2026

Every Day Counts—Or Does It? Day Counts Revisited

Mayer Brown
Mayer Brown
Contributor
Mayer Brown

Mayer Brown

Mayer Brown is a leading international law firm positioned to represent the world’s major...

View firm profile
Explore more from Mayer Brown

For most of the year, calendar days, business days and trading days are the same. Then holidays happen and confuse things. What are the different types of days, and why does it matter?

United StatesFinance and Banking
Bradley Berman
Bradley Berman
Elizabeth Encinas
Elizabeth Encinas
Marla Matusic
Marla Matusic
Anna T. Pinedo
Anna T. Pinedo
Declan Goulding
Declan Goulding
Author LinkedIn connections

For most of the year, calendar days, business days and trading days are the same. Then holidays happen and confuse things. What are the different types of days, and why does it matter?

Calendar days are just what they sound like – they include every day on the calendar and are used to compute interest.

Trading days are days on which the relevant stock exchanges are open. In the United States, the New York Stock Exchange and the Nasdaq exchanges observe the same holiday schedule. A half-day of trading is also considered a “good” trading day when calculating a day-count.

Trading days (and business days for that matter) are distinct from days on which EDGAR will be operational and accept filings. EDGAR’s calendar of “good filing days” is available on the SEC website. The SEC will also issue announcements with respect to additional holidays that may occur. It is important to always check for recent announcements because the main calendar is not updated for special holidays.

We operate a free-to-view policy, asking only that you register in order to read all of our content. Please login or register to view the rest of this article.

Register for freeORLog in

Visit us at mayerbrown.com

Mayer Brown is a global services provider comprising associated legal practices that are separate entities, including Mayer Brown LLP (Illinois, USA), Mayer Brown International LLP (England & Wales), Mayer Brown (a Hong Kong partnership) and Tauil & Chequer Advogados (a Brazilian law partnership) and non-legal service providers, which provide consultancy services (collectively, the "Mayer Brown Practices"). The Mayer Brown Practices are established in various jurisdictions and may be a legal person or a partnership. PK Wong & Nair LLC ("PKWN") is the constituent Singapore law practice of our licensed joint law venture in Singapore, Mayer Brown PK Wong & Nair Pte. Ltd. Details of the individual Mayer Brown Practices and PKWN can be found in the Legal Notices section of our website. "Mayer Brown" and the Mayer Brown logo are the trademarks of Mayer Brown.

© Copyright 2026. The Mayer Brown Practices. All rights reserved.

This Mayer Brown article provides information and comments on legal issues and developments of interest. The foregoing is not a comprehensive treatment of the subject matter covered and is not intended to provide legal advice. Readers should seek specific legal advice before taking any action with respect to the matters discussed herein.

View source

Related Articles

Legal Intelligence Newsletters: sign up for the latest legal and regulatory news on your chosen topics

Read more about

Related Comparative Guides

See more popular content from

Article

SEC Advances “Responsible Retailization” Through A Potential Accredited Investor Exam And Potential Regulated Fund Reforms

On September 30, 2026, the Securities and Exchange Commission (SEC) issued two rule proposals and five notices aimed at expanding investors’ access to private markets. The package would add ways to qualify as an accredited investor, including passing a new exam administered by the Financial Industry Regulatory Authority (FINRA), broaden performance-based compensation and modernize regulated funds, including interval funds and business development companies (BDCs).
United StatesFinance and Banking
Proskauer Rose LLP
Proskauer Rose LLP
Article

SEC Proposes Rule Amendments To Expand Retail Access To Private Markets

The SEC has proposed sweeping amendments to expand retail investor access to private market strategies, including changes to performance-based compensation rules for registered investment advisers and modernization of the interval fund framework. The proposals also explore new credential-based pathways for individuals to qualify as accredited investors, potentially opening private offerings to a broader pool of eligible participants.
United StatesFinance and Banking
Duane Morris LLP
Duane Morris LLP
Article

SEC Approves FINRA’s New “Outside Activities” Rule

The Securities and Exchange Commission has approved FINRA Rule 3290, which will replace existing rules governing outside business activities and private securities transactions for registered persons. This new rule narrows the scope to focus on investment-related activities while maintaining similar supervisory obligations for member firms. Understanding the key changes and implementation requirements will be critical for broker-dealers as they update their compliance policies and procedures.
United StatesFinance and Banking
WilmerHale
WilmerHale
Article

New NYSE Delisting Rules: What Microcap Companies Need To Know About The $0.25 Minimum Trading Price

The SEC has approved new NYSE and NYSE American listing rules establishing a $0.25 minimum trading price, effective July 1, 2027. A single closing price below this threshold triggers immediate trading suspension and delisting proceedings with no cure period. Companies trading at low share prices must act now during the transition period to implement reverse stock splits and establish monitoring procedures before this hard floor takes effect.
United StatesFinance and Banking
Bevilacqua
Bevilacqua
Article

SEC Proposes Rule Changes And Seeks Comments On Additional Accredited Investor Pathways

The Securities and Exchange Commission has proposed six new pathways for individuals to qualify as accredited investors, moving beyond traditional income and wealth thresholds. These changes would allow qualification through professional certifications like CPA, CFA, and CFP designations, as well as through a new FINRA-administered exam testing securities knowledge.
United StatesFinance and Banking
Taft, Stettinius & Hollister LLP
Taft, Stettinius & Hollister LLP
Article

DOL Announces Enforcement Actions Against Employers In H-1B And PERM Fraud Probe

The Trump Administration has launched an unprecedented enforcement action suspending permanent labor certification processing for eight major employers, linking immigration sponsorship to layoff histories and recruitment practices. This development signals a fundamental shift in how the government evaluates employer access to H-1B and green card programs, with investigations already underway and subpoenas served.
United StatesEmployment and HR
Mayer Brown
Mayer Brown
Article

Trump Administration Announces New Enforcement Actions Against Employers In H-1B And PERM Fraud Probes

The Trump Administration has launched an unprecedented investigation into H-1B visa and PERM labor certification programs, with the Department of Labor's Office of Inspector General issuing dozens of subpoenas and suspending employers' ability to process applications. Federal agencies are deploying new enforcement tools including whistleblower programs and criminal prosecution threats...
United StatesImmigration
Mayer Brown
Mayer Brown
Article

SEC Staff Statement On Fair Value Measurement And Disclosure Considerations For Private Assets

The SEC Staff has issued new guidance addressing fair value measurement and disclosure practices for private credit and other illiquid assets held by registered funds and business development companies. As private credit portfolios have grown nearly 60% since 2020, reaching $270 billion, regulators emphasize the critical importance of robust valuation methodologies, transparent disclosure of significant judgments, and careful application of accounting standards when market prices are unavailable.
United StatesAccounting and Audit
Mayer Brown
Mayer Brown
Article

AI Regulation In Singapore And Hong Kong: A Mid-Year Checkpoint

Singapore and Hong Kong continue to regulate artificial intelligence through existing laws and voluntary frameworks rather than comprehensive AI statutes, but the first half of 2026 has brought sharper emphasis on practical controls including agentic AI governance, assurance and testing, financial-sector oversight and cyber resilience. Both jurisdictions are building concrete expectations around risk management, transparency, human accountability and operational safeguards while avoiding horizontal AI legis
GlobalStrategy
Mayer Brown
Mayer Brown
Article

European Union Adopts 21st Package Against Russia & Parallel Sanctions On Belarus

The European Union has adopted its 21st package of sanctions against Russia and Belarus, significantly expanding restrictions across finance, energy, crypto, and military-industrial sectors. This comprehensive package introduces 218 new designations, freezes the oil price cap, imposes stricter LNG controls, and closes loopholes while reinforcing measures to discourage third-party sanctions evasion. The sanctions also strengthen protections for EU operators and facilitate business exits from Russia.
European UnionInternational Law
Mayer Brown
Mayer Brown
Article

Russia/Ukraine Sanctions Update - Month Of August 2026

This monthly update tracks the latest developments in Russia/Ukraine sanctions across US, EU, and UK jurisdictions, covering new designations, general license extensions, legislative proposals, and enforcement actions. The update also examines Russia's countermeasures, including shadow fleet expansion and legal restrictions on foreign investors, while highlighting international coordination efforts by Switzerland, Canada, and New Zealand.
GlobalInternational Law
Mayer Brown
Mayer Brown
Article

DOL Announces New Enforcement Policy For Mental Health Parity Nonquantitative Treatment Limitation Requirements

The US Department of Labor has issued new guidance establishing a streamlined framework for enforcing mental health parity requirements under MHPAEA, focusing enforcement on three priority areas while maintaining nonenforcement of controversial 2024 rule provisions. This guidance aims to reduce compliance burdens on plan sponsors while ensuring participants maintain access to mental health and substance use disorder benefits comparable to medical and surgical coverage.
United StatesEmployment and HR
Mayer Brown
Mayer Brown