# init(frame:columnName:timeUnit:) Creates a row grouping from a column with date or time elements. ``` init(frame: D, columnName: String, timeUnit: Calendar.Component) where GroupingKey == Int, D : DataFrameProtocol ``` ## Parameters `frame` A data frame type. `columnName` The name of the column that stores a row’s date and time information. `timeUnit` A calendar component that tells the row grouping how to create its groups. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)