Current Streak for Subject

mscopuser Sure, it's almost identical. Attached PBIX file below sig has the Current Streak measure as well as an example of Longest Streak for Project instead of sub-project.

Current Streak Sub-Project = 
    VAR __SubProject = MAX( 'Table'[Sub-projects] )
    VAR __MaxDate = MAXX( ALL( 'Table' ), [Start date] )
    VAR __MinDate = 
        MINX( 
            FILTER( 
                ALL( 'Table' ), 
                [Sub-projects] = __SubProject 
            ), 
            [Start date] 
        )
    VAR __Table = 
        ADDCOLUMNS(
            CALENDAR( __MinDate, __MaxDate ),
            "__Count", 
                VAR __Date = [Date]
                VAR __Result = 
                    IF( 
                        COUNTROWS( 
                            FILTER( 
                                ALL( 'Table' ), 
                                [Start date] = __Date && [Sub-projects] = __SubProject 
                            ) 
                        ), 1, 0 
                    )
            RETURN
                __Result
        )
    VAR __Table1 = 
        ADDCOLUMNS(
            __Table,
            "Cthulhu", 
                VAR __Index = [Date]
                VAR __Group = [__Count]
                VAR __TmpTable1 = FILTER( __Table, [__Count] = __Group && [Date] < __Index)
                VAR __TmpTable2 = 
                    ADDCOLUMNS( 
                        __TmpTable1, 
                        "__diff", 
                        ( 
                            [Date] - 
                            MAXX( 
                                FILTER( 
                                    __Table, 
                                    [Date] < EARLIER( [Date] ) && [__Count] = EARLIER( [__Count] ) 
                                ), 
                                [Date] 
                            ) 
                        ) * 1. 
                    )
                VAR __Max = MAXX( __TmpTable2, [Date])
                VAR __MaxStart = MAXX( FILTER(__TmpTable2, [__diff] > 1), [Date])
                VAR __TmpTable3 = FILTER( __TmpTable2, [Date] >= __MaxStart)
                VAR __Result = 
                    SWITCH( TRUE(),
                        ISBLANK( __Max ), 1, 
                        __Max = __index - 1, COUNTROWS( __TmpTable3 ) + 1, 
                        1
                    )
            RETURN
                __Result
        )
    VAR __CurrentCount = MAXX( FILTER( __Table1, [Date] = __MaxDate ), [__Count] )
    VAR __Result = IF( __CurrentCount = 0, 0, MAXX( FILTER( __Table1, [Date] = __MaxDate ), [Cthulhu] ) )
RETURN
    __Result