Visualizing Case Trends with Subscription Start and End Dates for Accounts

Hi Ricky97 
In power bi line chart you would not be able to create a x axis constant line for categorical or text label. If you have number in X axis, then you can create constant line to identify subscription start and end date. But in your case it is a categorical.

You need to use custome visual which provide such functionality.

However, you could get similar artifact using Line and Stacked column chart. See Some of the examples:

Here is the data model:

Created few extra column in Subscription table, See code below:

MonthYearSubscriptionTable = FORMAT('Subscription'[START DATE], "MMM-YYYY")

MonthYearEndDate = FORMAT('Subscription'[END DATE], "MMM-YYYY")

Image:

To create a column for Subscription Start Date, Use this measure:

CheckMonthYearMatch = 
IF(
    CALCULATE(
        COUNTROWS('Subscription'),
        'Subscription'[MonthYearSubscriptionTable] = SELECTEDVALUE('Calendar'[Month-Year])
    ) > 0,
    7,
    BLANK()
)

 To create a column for Subscription End Date, Use this measure:

CheckMonthYearMatchEnd = 
IF(
    CALCULATE(
        COUNTROWS('Subscription'),
        'Subscription'[MonthYearEndDate] = SELECTEDVALUE('Calendar'[Month-Year])
    ) > 0,
    7, // You could use measure to get the max count within all month, to set the hight of the column
    BLANK()
)

For custom data label for columns, Create below measure for Subscription Start Date:

CheckMonthYearMatchStartDate = 
IF(
    CALCULATE(
        COUNTROWS('Subscription'),
        'Subscription'[MonthYearSubscriptionTable] = SELECTEDVALUE('Calendar'[Month-Year])
    ) > 0,
    "Start Date : " & FORMAT(MINX(
        FILTER(
            'Subscription',
            'Subscription'[MonthYearSubscriptionTable] = SELECTEDVALUE('Calendar'[Month-Year])
        ),
        'Subscription'[START DATE]
    ), "MM-DD-YY") & " " &
    MINX(
        FILTER(
            'Subscription',
            'Subscription'[MonthYearSubscriptionTable] = SELECTEDVALUE('Calendar'[Month-Year])
        ),
        'Subscription'[CR Name]
    ),
    BLANK()
)

For Subscription End Date:

CheckMonthYearMatchEndDate = 
IF(
    CALCULATE(
        COUNTROWS('Subscription'),
        'Subscription'[MonthYearEndDate] = SELECTEDVALUE('Calendar'[Month-Year])
    ) > 0,
    "End Date : " & FORMAT(MINX(
        FILTER(
            'Subscription',
            'Subscription'[MonthYearEndDate] = SELECTEDVALUE('Calendar'[Month-Year])
        ),
        'Subscription'[END DATE]
    ), "MM-DD-YY") & " " & 
    MINX(
        FILTER(
            'Subscription',
            'Subscription'[MonthYearEndDate] = SELECTEDVALUE('Calendar'[Month-Year])
        ),
        'Subscription'[CR Name]
    ),
    BLANK()
)

Place measure to create Visual column in the visual Column-Y Axis, and CountCase measure in the Line Y-Axis:

Update data labels with the corresponding measure, see image :

PBIX : 

Hope this helps!!

If this solved your problem, please accept it as a solution and a kudos!!

Best Regards,
Shahariar Hafiz