sascha/esphome
1
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2026-02-08 00:31:58 +00:00
Code Issues Releases Wiki Activity

ambig time

Browse Source
This commit is contained in:
J. Nick Koston
2026-01-30 00:38:29 -06:00
parent 22ab20ba4c
commit a93e3b6fa0
1 changed files with 26 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
esphome/core/time.cpp
View File

@@ -268,14 +268,33 @@ void ESPTime::recalc_timestamp_local() {
// POSIX: local = utc - offset, so utc = local + offset
const auto &tz = time::get_global_tz();
// Use standard offset as initial guess to determine DST status
time_t approx_utc = this->timestamp + tz.std_offset_seconds;
// Check if DST is in effect and apply the appropriate offset
if (time::is_in_dst(approx_utc, tz)) {
this->timestamp += tz.dst_offset_seconds;
} else {
if (!tz.has_dst) {
// No DST - just apply standard offset
this->timestamp += tz.std_offset_seconds;
return;
}
// Try both interpretations to match libc mktime() with tm_isdst=-1
// For ambiguous times (fall-back repeated hour), libc prefers DST
// For invalid times (spring-forward skipped hour), libc normalizes to DST
time_t utc_if_dst = this->timestamp + tz.dst_offset_seconds;
time_t utc_if_std = this->timestamp + tz.std_offset_seconds;
bool dst_valid = time::is_in_dst(utc_if_dst, tz);
bool std_valid = !time::is_in_dst(utc_if_std, tz);
if (dst_valid && std_valid) {
// Ambiguous time (repeated hour during fall-back) - prefer DST to match libc
this->timestamp = utc_if_dst;
} else if (dst_valid) {
// Only DST interpretation is valid
this->timestamp = utc_if_dst;
} else if (std_valid) {
// Only standard interpretation is valid
this->timestamp = utc_if_std;
} else {
// Invalid time (skipped hour during spring-forward) - use DST to match libc
this->timestamp = utc_if_dst;
}
#else
// No timezone support - treat as UTC