Mac HFS+ Timestamp to Human-Readable Date Converter

The Mac HFS+ timestamp, also known as the Apple HFS+ timestamp, represents the number of seconds since midnight, January 1, 1904, GMT. This timestamp format is used in Apple's HFS+ file system, as well as in other systems like iPods, Palm OS, and JMP/JSL datetime. This tool allows you to convert these timestamps into human-readable dates for easier interpretation and debugging.

Historical Background

The HFS+ (Hierarchical File System Plus) is a file system developed by Apple for use on macOS and earlier versions of Mac OS. The HFS+ timestamp is based on the Mac OS epoch, which starts from January 1, 1904, instead of the Unix epoch (January 1, 1970). This difference is crucial when converting these timestamps to human-readable formats.

Calculation Formula

To convert an HFS+ timestamp to a human-readable date, follow these steps:

1. Subtract the difference between the HFS+ and Unix epochs: \[ \text{Unix Timestamp} = \text{HFS+ Timestamp} - 2,082,844,800 \] (where \(2,082,844,800\) is the number of seconds between January 1, 1904, and January 1, 1970).

2. Convert to a human-readable date: \[ \text{Human-Readable Date} = \text{Date}(\text{Unix Timestamp} \times 1,000) \]

Example Calculation

For an HFS+ timestamp of 3823414018:

1. Subtract the epoch difference: \[ \text{Unix Timestamp} = 3,823,414,018 - 2,082,844,800 = 1,740,569,218 \]

2. Convert to a human-readable date: \[ \text{Human-Readable Date} = \text{Date}(1,740,569,218 \times 1,000) = \text{Sun, 26 Feb 2025 11:07:06 GMT} \]

Importance and Usage Scenarios

This conversion is particularly useful for:

• Debugging HFS+ File Systems: Interpreting timestamps in logs or debugging sessions.
• Data Recovery: Converting timestamps when recovering data from HFS+ file systems.
• Cross-Platform Compatibility: Translating HFS+ timestamps for use in systems that use Unix timestamps.

Common FAQs

1. What is the difference between an HFS+ timestamp and a Unix timestamp?

   • An HFS+ timestamp is counted from January 1, 1904, while a Unix timestamp is counted from January 1, 1970. The difference between them is 2,082,844,800 seconds.

2. Can I convert HFS+ timestamps to other date formats?

   • Yes, after converting to a Unix timestamp, you can format the date in any desired format using JavaScript or other programming languages.

3. Where are HFS+ timestamps commonly used?

   • HFS+ timestamps are used in Apple's HFS+ file system, as well as in iPods, Palm OS, and JMP/JSL datetime.

This tool simplifies the process of converting Mac HFS+ timestamps into human-readable dates, making it easier to work with these timestamps in various scenarios.