Re: Wallclock - calendar option
Bernard Fouché <bernard.fouche <at> kuantic.com>
2012-02-14 14:44:50 GMT
Le 14/02/2012 12:09, qber_ a écrit :
> Hello all.
> I want to discuss an option of Wallclock device framework.. Now the wallclock supports two option :
init_get and set_get. This functions support time counted from 1970-01-01 00:00:00. The idea is to add
the support for calendar insted of seconds counter. Most of applications uses calendar not seconds counter.
> The change for handling date and time for me is a result of working with STM32F2x processor which has
calendar based RTC. The is no sense for converting calendar to seconds and then back again to calendar.
> The problem is which date and time format should be selected (if this change will be added to officail reposotory).
> Best Regards
time_t (or any similar integer counter) is used everywhere inside CPUs,
calendar time is used only to interface with entities externals to the
MCU/CPU like humans, files/databases, network. Usually there is much
more internal time calculations than time data output from a CPU in
calendar representation. It's very hard to see any gain by using
nightmarish calendar calculations when simple integer arithmetic can be
used instead. Write a function that adds a variable amount of time to
data represented as calendar date/time and compare it to an integer
addition. Conversion functions between time_t and calendar date/time
exist from 1970-01-01 00:00:00. Even Windows uses an integer
representation, even probably the Maya as shown by their overflow
problem at the end of the year.