DATEDIFF (MONTH): DATEDIFF( Earliest[Date], Latest[Date], MONTH ) : Months between two dates

QUARTER(): QUARTER( Orders[Order Date] ) : Quarter number of date

HASONEFILTER(): HASONEFILTER( Date[Year] ) : Check if column filtered

USERCULTURE(): USERCULTURE() : Return locale of user

ISOWeekNum(): WEEKNUM( Date[Date], 21 ) : ISO week number alternative

ISERROR(): ISERROR( [Measure] ) : Check if measure returns error

ISEVEN(): ISEVEN( Data[Index] ) : Test even number

ISODD(): ISODD( Data[Index] ) : Test odd number

NETWORKDAYS(): NETWORKDAYS( Start, End ): Working days between dates (custom func)

EARLIER(): EARLIER( Table[Column] ) : Access outer row context (again)