WhatWeek

Fast, ISO-aware week number tool

What Week Is It?

It is ISO Week 33 of 2026.

Based on UTC.

WEEK CONSOLE

Week 33

ISO week 2026-W33
Date range
Monday, August 10, 2026 – Sunday, August 16, 2026
Time zone
UTC
  • US-style Week 33
  • Remaining 20 ISO weeks remain
  • 62% ISO year 62% of the ISO year has elapsed
    ISO year progress 62% elapsed
  • Year length 2026 has 53 ISO weeks
Week at a glance 2026-W33
  1. Mon 10
  2. Tue 11
  3. Wed 12
  4. Thu 13
  5. Fri 14
  6. Sat 15
  7. Sun 16

Find the current ISO week number, date range, US-style week number, and verified holiday context when available.

  • ISO-aware
  • Time zone aware
  • US-style comparison

Quick converter

Convert a date to an ISO or US-style week number.

Type any IANA time zone, such as Europe/Paris or America/Los_Angeles.
Week system

ISO vs US-style week numbers

The same date can belong to different week numbers depending on the week system.

ISO week

2026-W33

ISO guide

Weeks start on Monday. Week 1 contains the first Thursday of the year.

Mon Tue Wed Thu Fri Sat Sun

US-style week

Week 33

US-style guide

Weeks start on Sunday. Week 1 contains January 1.

Sun Mon Tue Wed Thu Fri Sat

Location-aware planning

Holiday planning by location

Holiday calendars depend on the country or region you choose. Use the date-to-week tool to view verified holiday data when it is available.

Choose a timezone and country

August 2026

UTC baseline calendar. ISO week numbers are in the first column.

View full 2026 calendar
Wk MonTueWedThuFriSatSun
31
32
33
34
35
36

Jump from the current week answer into converters, calendars, and developer references.

Explore the API

Why week numbers differ

ISO weeks start on Monday and define Week 1 as the week containing the first Thursday of the year. US-style weeks usually start on Sunday and count the week containing January 1 as Week 1. Around New Year, these systems often show different week years and week numbers.

FAQ

What is the current ISO week?

The current ISO week is 2026-W33, based on UTC. The answer at the top is personalized to your browser timezone when available.

Does 2026 have 53 ISO weeks?

Yes. 2026 has 53 ISO weeks, and Week 53 runs from Monday, December 28, 2026 to Sunday, January 3, 2027.

Why is the US-style week number different?

US-style week numbering starts weeks on Sunday and counts Week 1 as the week containing January 1, so it can differ from ISO around New Year.