To start, log into Ignite and navigate to the options button in the top right corner. Click on the Administration Tab -> Advanced Options. At the top left, there is a box that says Support Options, go ahead and check that. Now scroll down until you find CUSTOM_TIME_MAX_RANGE_IN_HOURS, you can edit this value to be greater than 24 hours.
Please note that this is very detailed data and will slow down your repository when you run the custom time drop down for greater intervals.(By default, checking the option will not slow down your Ignite, just selecting large time frames will when you utilize this option will.) Depending on your environment, setup, and hardware you will want to use some caution.
Once this value has been adjusted, navigate back to your Home screen. Click on the instance you'd like to monitor -> select Custom Time Interval from the Day drop down on the Trend page, and enjoy analyzing your new data range!
Please let me know if this did not answer your question or if you have any other questions / issues.