Time Format
Plot stores time data as the number of seconds relative to an absolute reference time: the first instant of 1 January, 2001, Greenwich Mean Time (GMT). Dates before then are stored as negative numbers; dates after then are stored as positive numbers.
To convert a UNIX time to a Plot time simply subtract 978307200.0 from the UNIX time.
Time format tokes
| %a | Abbreviated weekday name |
| %A | Full weekday name |
| %b | Abbreviated month name |
| %B | Full month name |
| %c | Shorthand for “x", the locale format for date and time |
| %d | Day of the month as a decimal number (01-31) |
| %e | Same as %d but does not print the leading 0 for days 1 through 9 (unlike strftime(), does not print a leading space) |
| %F | Milliseconds as a decimal number (000-999) |
| %H | Hour based on a 24-hour clock as a decimal number (00-23) |
| %I | Hour based on a 12-hour clock as a decimal number (01-12) |
| %j | Day of the year as a decimal number (001-366) |
| %m | Month as a decimal number (01-12) |
| %M | Minute as a decimal number (00-59) |
| %p | AM/PM designation for the locale |
| %S | Second as a decimal number (00-59) |
| %w | Weekday as a decimal number (0-6), where Sunday is 0 |
| %x | Date using the date representation for the locale, including the time zone (produces different results from strftime()) |
| %X | Time using the time representation for the locale (produces different results from strftime()) |
| %y | Year without century (00-99) |
| %Y | Year with century (such as 1990) |
| %Z | Time zone name (such as Pacific Daylight Time; produces different results from strftime()) |
| %z | Time zone offset in hours and minutes from GMT (HHMM) |