Line 7: File reference date and revision date
2008 01 01 2008 06 24
<reference date year> <reference date month> <reference
date day> <revision date year> <revision date month>
<revision date day>
The file reference date
indicates the start point of the time axis in the file. The time axis is
always stated in days and begins at 00 UTC on the file reference date.
For example, a time stamp for 5 January 2008, 0 UTC may be stated with a
reference date of 2008 01 05 in line 7 and a day of 0 in the data
section, or with a reference date of 2008 01 01 in line 7 and a day of 4
in the data section.
The revision date is the date
when the file was created or last updated. Both dates are space
separated, and stated in the format
YYYY MM DD.