On a recent year when Monday fell on September 26 (for example, 2022), that date lined up with several observances rather than a single universal “big” holiday.

Key holidays on Monday, September 26 (example: 2022)

In 2022, September 26 was a Monday, so it’s a good reference point for “what holiday is Monday September 26.”

Some notable observances on that day included:

  • World Environmental Health Day (global awareness day).
  • World Contraception Day (international health-focused observance).
  • European Day of Languages (language and culture celebration in Europe).
  • Mesothelioma Awareness Day (health/awareness in the U.S. and beyond).
  • National Pancake Day (popular “fun” food day, observed in various calendars).
  • Johnny Appleseed Day (mainly in the U.S.).
  • National Dumpling Day (food observance).
  • Several family‑focused observances like “Family Day” / “Eat Dinner with Your Family Day.”

On the religious/public-holiday side, September 26, 2022 also coincided with:

  • The start of Rosh Hashanah (Jewish New Year, beginning the evening before).
  • Regional public holidays such as the King’s Birthday in parts of Australia and Ancestors’ Day in Cambodia.

Quick table of examples (for Monday, Sept 26, 2022)

html

<table>
  <tr>
    <th>Type</th>
    <th>Holiday / Observance</th>
    <th>Where / Context</th>
  </tr>
  <tr>
    <td>Religious</td>
    <td>Rosh Hashanah (start)</td>
    <td>Jewish communities worldwide[web:3][web:5]</td>
  </tr>
  <tr>
    <td>Public holiday</td>
    <td>King's Birthday</td>
    <td>Some Australian states[web:3][web:9]</td>
  </tr>
  <tr>
    <td>Public holiday</td>
    <td>Ancestors' Day (Pchum Ben)</td>
    <td>Cambodia[web:3][web:9]</td>
  </tr>
  <tr>
    <td>Awareness day</td>
    <td>World Environmental Health Day</td>
    <td>International[web:1]</td>
  </tr>
  <tr>
    <td>Awareness day</td>
    <td>Mesothelioma Awareness Day</td>
    <td>Mainly U.S., global awareness[web:1][web:5]</td>
  </tr>
  <tr>
    <td>Fun/food day</td>
    <td>National Pancake Day</td>
    <td>Listed in multiple “day” calendars[web:1][web:3]</td>
  </tr>
  <tr>
    <td>Fun/food day</td>
    <td>National Dumpling Day</td>
    <td>Primarily U.S.-style observance[web:1][web:5]</td>
  </tr>
  <tr>
    <td>Cultural/linguistic</td>
    <td>European Day of Languages</td>
    <td>Europe-focused, promoted by Council of Europe[web:5]</td>
  </tr>
</table>

Mini “forum style” note

If someone on a forum asks “what holiday is Monday September 26,” the honest answer is that it depends on the country and year, and there isn’t one single worldwide holiday for that date—rather, it’s packed with various international, national, and “fun” observances, plus regional public holidays like the King’s Birthday in parts of Australia and religious observances like Rosh Hashanah.

TL;DR

  • Monday, September 26 (e.g., in 2022) is not one universal global holiday.
  • It features multiple observances such as World Environmental Health Day, World Contraception Day, Mesothelioma Awareness Day, European Day of Languages, National Pancake Day, Johnny Appleseed Day, and more, plus regional public holidays and the start of Rosh Hashanah in that year.

Information gathered from public forums or data available on the internet and portrayed here.