SAS Timestamp to Human-Readable Date Converter (Seconds or Days since 1960)

The SAS timestamp represents the number of seconds or days since January 1, 1960, and is commonly used in the SAS programming language for statistical analysis. This tool converts SAS timestamps into human-readable dates, making it easier to work with data in SAS and integrate it with other systems.

Historical Background

SAS (Statistical Analysis System) is a programming language developed in the 1960s for data management, advanced analytics, and statistical analysis. The SAS timestamp system, which counts time from January 1, 1960, is widely used in datasets and reports generated using SAS. Understanding and converting these timestamps is essential for interpreting data and integrating it with systems that use Unix timestamps.

Calculation Formula

To convert a SAS timestamp to a human-readable date, follow these steps:

1. For SAS datetime (seconds since 1960): \[ \text{Unix Timestamp} = \text{SAS Timestamp} + 315,619,200 \] (where \(315,619,200\) is the number of seconds between January 1, 1960, and January 1, 1970).

2. For SAS date (days since 1960): \[ \text{Unix Timestamp} = (\text{SAS Timestamp} \times 86,400) + 315,619,200 \] (where \(86,400\) is the number of seconds in a day).

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

Example Calculation

For a SAS datetime timestamp of 2056189036 (in seconds):

1. Add the epoch difference: \[ \text{Unix Timestamp} = 2,056,189,036 + 315,619,200 = 2,371,808,236 \]

2. Convert to a human-readable date: \[ \text{Human-Readable Date} = \text{Date}(2,371,808,236 \times 1,000) = \text{Sun, 26 Feb 2025 11:07:06 GMT} \]

For a SAS date timestamp of 23798 (in days):

1. Convert to seconds and add the epoch difference: \[ \text{Unix Timestamp} = (23,798 \times 86,400) + 315,619,200 = 2,371,808,236 \]

2. Convert to a human-readable date: \[ \text{Human-Readable Date} = \text{Date}(2,371,808,236 \times 1,000) = \text{Sun, 26 Feb 2025 11:07:06 GMT} \]

Importance and Usage Scenarios

This conversion is particularly useful for:

• Data Integration: Translating SAS timestamps for use in systems that rely on Unix timestamps.
• Statistical Analysis: Interpreting timestamps in SAS datasets for time-based analysis.
• Reporting: Converting SAS timestamps into readable formats for reports and visualizations.

Common FAQs

1. What is the difference between SAS datetime and SAS date?

   • SAS datetime is the number of seconds since January 1, 1960, while SAS date is the number of days since the same date.

2. How do I know if my SAS timestamp is in seconds or days?

   • SAS datetime timestamps are typically larger (9–10 digits), while SAS date timestamps are smaller (4–5 digits).

3. Can I convert SAS 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.

This tool simplifies the process of converting SAS timestamps into human-readable dates, making it easier to work with data in SAS and integrate it with other systems.