time-extra | Extra functions for working with Posix times from elm/time | Date Time Utils library

The "1" is parameterized, and as a result the group by expression is not "equal" from the select expression at query execution planning time. You have to use a constant for 1. I.e. .subtact(Expressions.numberTemplate(Integer.class, "1")).

Furthermore, I believe QueryDSL adds 1 to DayOfWeek for it to be consistent with Java's Day of Week rather than the DayOfWeek defined in ANSI SQL. You could consider using a custom instance of JPQLTemplates that defines a different standard template for the DAY_OF_WEEK operator (and renders the constant there). This can than be a safer default in your application.

Alternatively, when using Hibernate 5.4.10 or newer, you can also use "group by alias": use dayOfWeek.as("dayOfWeekAlias") in your select expression, and then use Expressions.numberPath(Integer.class, "dayOfWeekAlias") in your group by clause: