The WAS scanner has a limit of 24 hours for a single scan. When it reaches 24 hours the scan will automatically stop. Depending on the size of the application it is possible that your app can take longer than 24hrs to complete a full vulnerability scan.
By looking at the scan report you may be able to see why the scan took so long.
Time limit means allowed time for scanning duration.
You can fine more information on link https://discussions.qualys.com/message/39556-scan-taking-too-long-time-limit-reached
Is the report completed after 24 hours of scanning? Can we continue the scanning
At the end of the scan, there will be a scan report made available for information on that single scan. If the scanning of your application takes more than one scan what I would recommend is once the scan has completed is to run a Web Application Report as this will bring all scan data together in one report.
Retrieving data ...