Support forum for Cumulus weather station software
https://cumulus.hosiene.co.uk/
If you google you can find loads more info and yes a year with 2 zeros or more i.e. 1900 or 2000 is not a leap year according to the rules to calculate dates.Actually for the people here there is a little bit of a story about thus date choice.
Logically a good starting date with the January 1, 1900, so why a off that date?
It turns out that many years ago Lotus 123 was one of the more popular spreadsheets in the marketplace. It also turns out that Lotus 123 had a date calculation bug in which it assumed that the year 1900 was a leap year.
So for issues of compatibility and making the calculations remain the same across the two products, Excel by design and on purpose adopted the same date calculation bug!
So when they were setting up the date calculations system for VBA, there was a decision made to offset it by one day, as that would result in the same number of days between two different dates as what you get in Excel and Lotus.
So in theory I can't really say the above is 100% true, but they simply just offset it by one day to be different and to reduce the confusion issue.
There is some explains and details here:
http://www.cpearson.com/excel/datetime.htm
1900 wasn't a leap year, but 2000 was.water01 wrote:a year with 2 zeros or more i.e. 1900 or 2000 is not a leap year according to the rules to calculate dates.
IIRC if the year is exactly divisible by 50 it's a leap year.steve wrote:1900 wasn't a leap year, but 2000 was.water01 wrote:a year with 2 zeros or more i.e. 1900 or 2000 is not a leap year according to the rules to calculate dates.
No, 'century' years have to be divisible by 400 to be leap year. 1900 is divisible by 50 but isn't a leap year.RayProudfoot wrote:IIRC if the year is exactly divisible by 50 it's a leap year.steve wrote:1900 wasn't a leap year, but 2000 was.water01 wrote:a year with 2 zeros or more i.e. 1900 or 2000 is not a leap year according to the rules to calculate dates.
Yep, that's it. I should have thought about it a bit more before posting.steve wrote:No, 'century' years have to be divisible by 400 to be leap year. 1900 is divisible by 50 but isn't a leap year.
Actually that won't help me either, since my station online date was before I started using Cumulus. I assume that webtag is hard-wired to show when Cumulus was first engaged, and can't be overwritten.water01 wrote:The webtag you should be using is #DaysSinceRecordsBegan.
That should do it! Thanks.Matt.j5b wrote:Stop Cumulus and edit the Cumulus.ini file. Adjust the date in the line starting with "StartDate=". Save the file and restart Cumulus as per here: https://cumulus.hosiene.co.uk/viewtopic.php?f=4&t=9670