A number that determines on which day the week begins.
Problems can occur if dates are entered as text. Dates should be entered by using the DATE function, or as results of other formulas or functions. The WEEKNUM function syntax has the following arguments: This system is the methodology specified in ISO 8601, which is commonly known as the European week numbering system. System 2 The week containing the first Thursday of the year is the first week of the year, and is numbered as week 1. System 1 The week containing January 1 is the first week of the year, and is numbered week 1. There are two systems used for this function: For example, the week containing January 1 is the first week of the year, and is numbered week 1. Returns the week number of a specific date. This article describes the formula syntax and usage of the WEEKNUM function Excel for Microsoft 365 Excel for Microsoft 365 for Mac Excel for the web Excel 2021 Excel 2021 for Mac Excel 2019 Excel 2019 for Mac Excel 2016 Excel 2016 for Mac Excel 2013 Excel 2010 Excel 2007 Excel for Mac 2011 Excel Starter 2010 More.
