Appendix A. Application Notes

A.1. PDF Date Format

PDF uses a special date format, which closely follows that of the international standard ASN.1 (Abstract Syntax Notation One), defined in ISO/IEC 8824. A date is a string of the form



  • YYYY is the year

  • MM is the month

  • DD is the day (01–31)

  • HH is the hour (00–23)

  • mm is the minute (00–59)

  • SS is the second (00–59)

  • O is the relationship of local time to Universal Time (UT), denoted by one of the characters +, -, or Z (see below)

  • HH followed by ' is the absolute value of the offset from UT in hours (00–23)

  • mm followed by ' is the absolute value of the offset from UT in minutes (00–59)

The quotation mark character (') after HH and mm is part of the syntax. All fields after the year are optional. (The prefix D:, although also optional, is strongly recommended.) The default values for MM and DD are both 01; all other numerical fields default to zero values. A plus sign (+) as the value of the O field signifies that local time is later than UT, a minus sign (-) that local time is earlier than UT, and the letter Z that local time is equal to UT. If no UT information is specified, the relationship of the specified time to UT is considered to be unknown. Whether or not the time zone is known, the rest of the date should be specified in local time.

For example, December 23, 1998, at 7:52 PM, U.S. Pacific Standard Time, is represented by the string,


PDFLeo allows more relaxed syntax. The starting D: can be skipped. You can specify YYYY or YYYMMDD only. For example, the following examples are valid:


A.2. Console Font in Windows

This program is fully Unicode compliant. In order to produce consistent output, all strings are outputted as UTF-8. If the output is redirected to a file, a UTF-8 capable viewer is required to view the contents correctly, such as notepad2, notepad++ and Internet Explorer under UTF-8 mode.

If you view the results at command line, set the console font to Lucida Console or a true type font that has most character sets available.

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This manual is specific to PDFLeo 1.0.
The current version is 1.0.0.

This Manual is also available in the following format: PDF.