I presume you mean the Uptime Calendar? The uptime calendar data is all dynamically generated and doesn't have fixed data in the database.
best way to get what you want is to use event log scanning and run a report to find events that indicate an asset was put into sleep mode.
You'll first have to enable scanning non-error events as mentioned here: https://www.lansweeper.com/knowledgebase/scanning-non-error-events/
Once enabled and assets are rescanned, you can create a report and filter for
event 42.