crawler.overall_crawl_timeout (collection.cfg setting)
This option specifies how many minutes, or hours, the crawler is allowed to run. The option crawler.overall_crawl_units specifies the unit of measure.
Note: This parameter can be left empty, in which case the crawler will keep going until there are no URLs left in its frontier, or it reaches another limit e.g. crawler.max_files_stored
If you are testing a new collection, then it can be useful to run a short crawl, say 10 minutes: