Hi,
i red there was a fix for the daylight saving
what are the date for daylight saving change for
1) What is "offline" daylight savings?
2) A fix for what problem? Do you have a reference?
3) To handle daylight savings, you must know the start date and the end date for the changes. These dates depends on in which country you are. Without that, you can't know when you should add/subtract the daylight-savings offset to the nordinary conversion between UTC and local time. You can't have daylight savings without knowing when it is "summer".
4) Most embedded systems don't have time-zone support or daylight-savings support. Perhaps you should describe your situation a bit better.
Just out of curiosity, do all countries that do so-called "daylight saving" apply the same offset at the same time across the whole nation?
Particularly thinking of the USA: is it a state thing, or a nationwide thing?
Also, are there any locations that adjust it by other than 1 hour?
yes ,run tzedit to see whindows setings
some have haf hour
There are (or have been) regions with other than 60 min adjustment, just as there are regions with the time zone being in-between full hours.
And there really are countries with more than one on/off date, so systems who care about DST have to be designed carefully - especially if configured by end users or if the units may move between different regions and time zones.
I'm not really fully up-to-date but I think Greenland currently have a different rule for the city Thule.
Having different on/off dates is very unusual, but an important thing is that a country can have time zones with and time zones without DST. For example Hawaii don't have DST, while most of US have. Brazil is also an example with regions with or without DST.
Because DST handling is politically controlled, an embedded system with such support should either have input fields for manual editing one year at a time, or support a table with start date/time, stop date/time and offset is stored for multiple years into the future.
This is a good reference for startup information about current time zones. Most Linux systems also comes fully loaded with the current rules for most regions of the world for as long as is currently known.
home.tiscali.nl/.../TZworld.html