Re: 32 bits time_t and Y2038 issue

On 2025-03-11, David Brown <david.brown@hesbynett.no> wrote:

package as-is.  For anything other than a quick demo, my preferred setup
is using makefiles for the build along with an ARM gcc toolchain.  That
way I can always build my software, from any system, and archive the
toolchain.  (One day, I will also try using clang with these packages,
but I haven't done so yet.)

Same here.  I just switched to ARM gcc + picolibc for all my ARM projects -
this required some changes in the way my makefiles generate linker scripts
and startup code, and now I am quite happy with that setup.


I have one project where I needed custom time functions: a nixie clock that
has both a RTC (with seconds/minutes/... registers), and NTP to get current
time. NTP time is seconds since 1.1.1900 and UTC.

The sane approach to handling timezones and DST is the unix way: keep
everything in UTC internally and convert to localtime when displaying the
time.  To set the RTC, that requires a version of mktime that does *not* do
timezone conversion - I simply pulled mktime from the newlib sources and
removed the timezone stuff - done.  You could write that stuff yourself, but
getting all the corner cases right will take some time.  The existing code
is there and works fine.

cu
Michael
--
Some people have no respect of age unless it is bottled.