The log file "year.ini" is where Cumulus software tracks the extremes for this year. Like alltime.ini this log file has section headings with lists of properties (attribute = value).
For more information on this file see in the Cumulus 1 help file, in the section “Data log file format”. This still applies for MX.
The sections (after the first [General]) can be in any order, Cumulus will maintain whatever order the sections are currently in. For readability you can insert blank lines into this file, Cumulus will not mind. Do not however introduce any punctuation nor change the format of any parameter line.
This log file holds the information that feeds the Webtags#Yearly for the 'thisyearT.htm' web template. So you won't find the yearly rainfall total in this file, that is not in that template.
Differences between Cumulus versions for this log file
The year functionality is not present prior to Cumulus 1.9.2 (build 1002 - 5 July 2011), so this file only exists for that and later builds of Cumulus 1, and all MX builds.
The sections that are included in this file vary by version. There are more for MX than there were for Cumulus 1. The sections are same as for month.ini.
Some Cumulus 1 builds did not store correct values for those using 9am/10am rollover, see alltime.ini for some examples.
Any date/time entries are in different formats for Cumulus 1 and Cumulus MX as illustrated for month.ini. That page also tells you that MX can read the Cumulus 1 date/time formats, so if you move a "year.ini" from Cumulus 1 you do not need to edit the date/time entries, MX will update them when its hits the first new extreme to record for the year.
If you do move "year.ini" from Cumulus 1 to Cumulus MX and were using a comma as your decimal separator (e.g. 12,1) you will need to edit your file and change each (e.g. 12,1) to use a full stop before MX can read it (e.g. 12.1).
Dealing with errors
The diagnostic logs in the 'diags' sub-folder for Cumulus 1 (and MXDiags for MX when full debugging switched on) record before and after values for updates to highs and lows for monthly and annual extreme records, and can help if this file is corrupted by a false extreme. The stored values can be corrected using the functionality available in both Cumulus 1 and MX for editing this year's records.
These lows and highs and their timestamps can be seen by picking the Highs and Lows - This year screen from the View menu (Cumulus 1 only - see picture on this page).