I think you forgot to attach your screenshot of the chart. Off the top of my head, what level of granularity are you using? For instance, if you are setting it to a resolution of one period (5 minutes) those will not exist for 30 days by default as this would increase the size of the database considerably. Try setting the resolution higher.
The list of all possible time ranges is divided into three sections: Current, Recent, and Historical.
This section includes the last 10 days.
DMI reports can be crafted to have sections override (or have different) time settings than the report. Edit the report (not the section) and look for different time settings in the report definition. There should be a "time" tab at the top of the report definition.
Time may be applied to a section, with different resolutions, than what is displayed when looking at the report. I think that may be what is happening to you. The section may have 1 hour resolution, and be cutting off your data as Shane described.
You may want to create a custom report and remove/modify the time settings for your purpose.
Thx for your reply, what I also have noticed:
The three graphs on the left use below view
The complete graph on the right uses below view
The month aggregate works fine,
Looking at my applications (with Appl, trans and tier view) , the 1 hour aggregate is also missing after 5 days.
Looking at my applications (with Software service, operation and Site data) no data is missing.
The Application, transaction, and tier data, 'Data Views' has some limitations on the aggregation and an exception for the 'Tier' dimension.
This data view provides dimensions and metrics that are common to different types of application layers (tiers). However, it does not allow data aggregation for different tiers on a report - the "Tier" dimension must always be selected when defining the report. The only exception to this rule is when you want to display data for front-end tiers. You do not have to use the "Tier" dimension if you set the "Tier type" to "Data center tier" and the "Is front-end tier" dimension to "Yes".