🔍 Trouver le numéro de semaine d'une date
Semaine 26
Numéro de semaine ISO
Lun Juin 22 – Dim Juin 28, 2026
| Week # | Lun (Start) | Dim (End) | Mois couverts | Trimestre | Jours |
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Questions fréquentes
What week number is it today?
Aujourd'hui est en Week -- of 2026. Semaines ISO start on Lundi and end on Dimanche.
How are ISO week numbers calculated?
ISO 8601 defines a week as starting on Lundi. Week 1 of a year is the week that contains the first Jeudi of the year (or equivalently, the week containing Janvier 4th). This means Janvier 1 can sometimes be in the last week of the previous year (Week 52 or 53).
How many weeks are in 2026?
2026 has 52 Semaines ISO. The year starts on Jeudi, Janvier 1, and ends on Jeudi, Décembre 31. Week 1 of 2026 begins on Lundi, Décembre 29, 2025.
What is the difference between ISO week and calendar week?
Semaines ISO (ISO 8601) always start on Lundi. In the US, calendar weeks often start on Dimanche. This means an ISO week number may differ from a US-style week number by 1 depending on the day. OnlineCalendar.org uses ISO 8601 week numbering.
When does Week 1 of 2027 start?
ISO Week 1 of 2027 starts on Lundi, Janvier 4, 2027 — because Janvier 1, 2027 falls on a Vendredi, and Week 53 of 2026 covers Déc 28, 2026 – Jan 3, 2027.