Alltime.ini
Cumulus maintains a number of 'all time records' for the station -- highs and lows for many of the readings. These were stored in a database file (alltime.rec) however starting with Build 924 (version 1.8.9) of Cumulus this data is now stored in a text file which can be easily edited if needed.
The first time you run Build 924 or later of Cumulus it will convert your alltime.rec file into an alltime.ini file and use the ini file going forward. The alltime.ini file is located in the 'data' folder
Date, Time and Decimal formatting is as per your regional settings on the PC running Cumulus.
Example line of the file
[Temperature] hightempvalue=30.7999992370605 hightemptime=27/06/2011 12:58:00 lowtempvalue=-12.5 lowtemptime=20/12/2010 07:17:00 lowchillvalue=-12.5 lowchilltime=20/12/2010 07:17:00 highmintempvalue=17.2999992370605 highmintemptime=10/07/2010 lowmaxtempvalue=-4.30000019073486 lowmaxtemptime=20/12/2010 highapptempvalue=33.7999992370605 highapptemptime=27/06/2011 12:50:00 lowapptempvalue=-15.8000001907349 lowapptemptime=20/12/2010 07:17:00 highheatindexvalue=34.2000007629395 highheatindextime=27/06/2011 13:09:00 highdewpointvalue=21.8999996185303 highdewpointtime=27/06/2011 13:09:00 lowdewpointvalue=-13.5 lowdewpointtime=20/12/2010 07:20:00 hightemprangevalue=20.3999996185303 hightemprangetime=20/04/2011 lowtemprangevalue=1.29999995231628 lowtemprangetime=31/12/2010 [Wind] highwindvalue=30.7578811645508 highwindtime=12/09/2011 09:08:32 highgustvalue=38.4000015258789 highgusttime=07/02/2011 10:34:00 highdailywindrunvalue=221.78596496582 highdailywindruntime=10/09/2011 23:59:00 [Rain] highrainratevalue=114.300003051758 highrainratetime=23/09/2010 14:13:00 highdailyrainvalue=34.9000015258789 highdailyraintime=17/07/2011 22:19:00 highhourlyrainvalue=15.8000001907349 highhourlyraintime=23/09/2010 22:08:00 highmonthlyrainvalue=103.599998474121 highmonthlyraintime=01/02/2011 longestdryperiodvalue=17 longestdryperiodtime=24/04/2010 longestwetperiodvalue=16 longestwetperiodtime=16/02/2011 [Pressure] highpressurevalue=1043.30004882813 highpressuretime=26/01/2010 10:44:00 lowpressurevalue=965.700012207031 lowpressuretime=08/11/2010 15:42:00 [Humidity] highhumidityvalue=100 highhumiditytime=23/01/2010 01:10:00 lowhumidityvalue=21 lowhumiditytime=24/04/2010 12:10:00