How long does the Mac keep diagnostic and usage data after it is generated?

The correct duration for how long a Mac keeps diagnostic and usage data after it is generated is indeed one month. This timeframe is established by macOS as part of its maintenance practices, allowing the system to gather enough data for analysis, while also managing storage by not retaining this data indefinitely.

Retaining data for one month strikes a balance between being useful for troubleshooting issues and maintaining user privacy. After this period, the system automatically purges older data to free up space and avoid accumulation of unnecessary information.

Other durations, such as one week or three months, do not align with Apple's data management protocols, and indefinite retention would not reflect the principles of customer privacy and system efficiency that Apple prioritizes.