[FIX]: Properly decode DVB EIT start time BCD field in XMLTV output

docs/CHANGES.TXT

@@ -1,5 +1,6 @@
 0.96.6 (unreleased)
 -------------------
+- Fix: DVB EIT start time BCD decoding in XMLTV output causing invalid timestamps (#1835)
 - New: Add Snap packaging support with Snapcraft configuration and GitHub Actions CI workflow. 
 - Fix: Clear status line output on Linux/WSL to prevent text artifacts (#2017)
 - Fix: Prevent infinite loop on truncated MKV files

src/lib_ccx/ts_tables_epg.c

@@ -136,6 +136,7 @@ void EPG_DVB_calc_start_time(struct EPG_event *event, uint64_t time)
 	if (mjd > 0)
 	{
 		long y, m, d, k;
+		struct tm timeinfo = {0};
 
 		// algo: ETSI EN 300 468 - ANNEX C
 		y = (long)((mjd - 15078.2) / 365.25);
@@ -145,7 +146,32 @@ void EPG_DVB_calc_start_time(struct EPG_event *event, uint64_t time)
 		y = y + k + 1900;
 		m = m - 1 - k * 12;
 
-		snprintf(event->start_time_string, sizeof(event->start_time_string), "%02ld%02ld%02ld%06" PRIu64 "+0000", y, m, d, time & 0xffffff);
+		timeinfo.tm_year = y - 1900;
+		timeinfo.tm_mon = m - 1;
+		timeinfo.tm_mday = d;
+
+		// Decode BCD time (lower 24 bits: HHMMSS)
+		uint32_t bcd = (uint32_t)(time & 0xFFFFFF);
+
+		timeinfo.tm_sec = (bcd & 0x0f) + (10 * ((bcd & 0xf0) >> 4));
+
+		timeinfo.tm_min = ((bcd & 0x0f00) >> 8) + (10 * ((bcd & 0xf000) >> 12));
+
+		timeinfo.tm_hour = ((bcd & 0x0f0000) >> 16) + (10 * ((bcd & 0xf00000) >> 20));
+
+		timeinfo.tm_isdst = -1;
+
+		mktime(&timeinfo);
+
+		snprintf(event->start_time_string,
+			 sizeof(event->start_time_string),
+			 "%04d%02d%02d%02d%02d%02d +0000",
+			 timeinfo.tm_year + 1900,
+			 timeinfo.tm_mon + 1,
+			 timeinfo.tm_mday,
+			 timeinfo.tm_hour,
+			 timeinfo.tm_min,
+			 timeinfo.tm_sec);
 	}
 }