Grasping Star Schema

Koppe008 , You can not have the order ID in Date table. You can create date table using calendar or calendar auto

example

Calendar = Addcolumns(calendar(date(2020,01,01), date(2021,12,31) ), "Month no" , month([date])
, "Year", year([date])
, "Month Year", format([date],"mmm-yyyy")
, "Month year sort", year([date])*100 + month([date])
, "Qtr Year", format([date],"yyyy-\QQ")
, "Qtr", quarter([date])
, "Month",FORMAT([Date],"mmmm")
, "Month sort", month([DAte])
, "FY Year", if( Month(_max) <7 , year(_max)-1 ,year(_max))
, "Is Today" ,if([Date]=TODAY(),"Today",[Date]&"")
,"Day of Year" , datediff(date(year([DAte]),1,1), [Date], day)+1
, "Month Type", Switch( True(),
eomonth([Date],0) = eomonth(Today(),-1),"Last Month" ,
eomonth([Date],0)= eomonth(Today(),0),"This Month" ,
Format([Date],"MMM-YYYY") )
,"Year Type" , Switch( True(),
year([Date])= year(Today()),"This Year" ,
year([Date])= year(Today())-1,"Last Year" ,
Format([Date],"YYYY")
)
)

To me the first one seems fine. Unless you have reason to merge