diff --git a/src/log_format.cc b/src/log_format.cc
index 9580b467..f3ec5fd5 100644
--- a/src/log_format.cc
+++ b/src/log_format.cc
@@ -308,9 +308,9 @@ void log_format::check_for_new_year(std::vector<logline> &dst, exttm etm,
     }
     if (diff > (60 * 24 * 60 * 60)) {
         off_year = 1;
-    } else if (diff > (15 * 24 * 60 * 60)) {
+    } else if (diff >= (24 * 60 * 60)) {
         off_month = 1;
-    } else if (diff > (12 * 60 * 60)) {
+    } else if (!(etm.et_flags & ETF_DAY_SET) && (diff >= (60 * 60))) {
         off_day = 1;
     } else if (!(etm.et_flags & ETF_DAY_SET)) {
         off_hour = 1;
@@ -321,7 +321,8 @@ void log_format::check_for_new_year(std::vector<logline> &dst, exttm etm,
     if (!do_change) {
         return;
     }
-    log_debug("%d:detected year change", dst.size());
+    log_debug("%d:detected time rollover; offsets=%d %d %d %d", dst.size(),
+              off_year, off_month, off_day, off_hour);
     for (iter = dst.begin(); iter != dst.end(); iter++) {
         time_t     ot = iter->get_time();
         struct tm otm;
@@ -329,7 +330,7 @@ void log_format::check_for_new_year(std::vector<logline> &dst, exttm etm,
         gmtime_r(&ot, &otm);
         otm.tm_year -= off_year;
         otm.tm_mon  -= off_month;
-        otm.tm_yday -= off_day;
+        otm.tm_mday -= off_day;
         otm.tm_hour -= off_hour;
         iter->set_time(tm2sec(&otm));
     }
@@ -731,8 +732,8 @@ log_format::scan_result_t external_log_format::scan(std::vector<logline> &dst,
         }
 
         if (!((log_time_tm.et_flags & ETF_DAY_SET) &&
-                (log_time_tm.et_flags & ETF_MONTH_SET) &&
-                (log_time_tm.et_flags & ETF_YEAR_SET))) {
+              (log_time_tm.et_flags & ETF_MONTH_SET) &&
+              (log_time_tm.et_flags & ETF_YEAR_SET))) {
             this->check_for_new_year(dst, log_time_tm, log_tv);
         }
 
diff --git a/test/Makefile.am b/test/Makefile.am
index 5d58b0e6..b15d7d87 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -279,6 +279,7 @@ dist_noinst_DATA = \
 	logfile_openam.0 \
 	logfile_plain.0 \
 	logfile_pretty.0 \
+	logfile_rollover.0 \
 	logfile_strace_log.0 \
 	logfile_syslog.0 \
 	logfile_syslog.1 \
diff --git a/test/logfile_rollover.0 b/test/logfile_rollover.0
new file mode 100644
index 00000000..f37fbabd
--- /dev/null
+++ b/test/logfile_rollover.0
@@ -0,0 +1,6 @@
+00:00:00.000 foo DEBUG  some super duper message
+01:00:00.000 foo DEBUG  some super duper message
+02:00:00.000 foo DEBUG  some super duper message
+03:00:00.000 foo DEBUG  some super duper message
+00:00:00.000 bar DEBUG  some super duper message next day (only one hour)
+00:01:00.000 bar DEBUG  some super duper message next day (only one hour)
diff --git a/test/test_logfile.sh b/test/test_logfile.sh
index 01b935d2..89512ba8 100644
--- a/test/test_logfile.sh
+++ b/test/test_logfile.sh
@@ -62,6 +62,18 @@ Dec 03 09:23:38 2006 -- 000
 Jan 03 09:47:02 2007 -- 000
 EOF
 
+touch -t 200711030000 ${srcdir}/logfile_rollover.0
+run_test ./drive_logfile -t -f generic_log ${srcdir}/logfile_rollover.0
+
+check_output "Generic timestamp interpreted incorrectly for day rollover?" <<EOF
+Nov 02 00:00:00 2007 -- 000
+Nov 02 01:00:00 2007 -- 000
+Nov 02 02:00:00 2007 -- 000
+Nov 02 03:00:00 2007 -- 000
+Nov 03 00:00:00 2007 -- 000
+Nov 03 00:01:00 2007 -- 000
+EOF
+
 gzip -c ${srcdir}/logfile_syslog.1 > logfile_syslog.1.gz
 
 run_test ./drive_logfile -t -f syslog_log logfile_syslog.1.gz