diff --git a/reference/track/simint1000m.csv b/reference/track/simint1000m.csv
new file mode 100644
index 000000000..4de8a125a
--- /dev/null
+++ b/reference/track/simint1000m.csv
@@ -0,0 +1,96 @@
+No,Latitude,Longitude,Date,Time
+1,66.000103,-179.979040,2022/01/01,00:00:00
+2,66.000146,-179.979035,2022/01/01,00:00:01
+3,66.000188,-179.979030,2022/01/01,00:00:02
+4,66.000106,-179.979250,2022/01/01,00:00:03
+5,66.000023,-179.979470,2022/01/01,00:00:04
+6,66.000034,-179.979775,2022/01/01,00:00:05
+7,66.000045,-179.980080,2022/01/01,00:00:06
+8,66.000111,-179.980280,2022/01/01,00:00:07
+9,66.000177,-179.980480,2022/01/01,00:00:08
+10,66.000143,-179.980575,2022/01/01,00:00:09
+11,66.000109,-179.980670,2022/01/01,00:00:10
+12,66.000138,-179.981320,2022/01/01,00:00:11
+13,66.000167,-179.981970,2022/01/01,00:00:12
+14,66.000121,-179.982585,2022/01/01,00:00:13
+15,66.000075,-179.983200,2022/01/01,00:00:14
+16,66.000105,-179.983745,2022/01/01,00:00:15
+17,66.000134,-179.984290,2022/01/01,00:00:16
+18,66.000128,-179.984740,2022/01/01,00:00:17
+19,66.000121,-179.985190,2022/01/01,00:00:18
+20,66.000159,-179.985385,2022/01/01,00:00:19
+21,66.000197,-179.985580,2022/01/01,00:00:20
+22,66.000177,-179.986145,2022/01/01,00:00:21
+23,66.000158,-179.986710,2022/01/01,00:00:22
+24,66.000148,-179.987380,2022/01/01,00:00:23
+25,66.000138,-179.988050,2022/01/01,00:00:24
+26,66.000154,-179.988555,2022/01/01,00:00:25
+27,66.000171,-179.989060,2022/01/01,00:00:26
+28,66.000111,-179.989380,2022/01/01,00:00:27
+29,66.000050,-179.989700,2022/01/01,00:00:28
+30,66.000058,-179.990500,2022/01/01,00:00:29
+31,66.000066,-179.991300,2022/01/01,00:00:30
+32,66.000056,-179.991565,2022/01/01,00:00:31
+33,66.000046,-179.991830,2022/01/01,00:00:32
+34,66.000089,-179.992615,2022/01/01,00:00:33
+35,66.000131,-179.993400,2022/01/01,00:00:34
+36,66.000110,-179.993620,2022/01/01,00:00:35
+37,66.000088,-179.993840,2022/01/01,00:00:36
+38,66.000127,-179.994440,2022/01/01,00:00:37
+39,66.000165,-179.995040,2022/01/01,00:00:38
+40,66.000180,-179.995500,2022/01/01,00:00:39
+41,66.000196,-179.995960,2022/01/01,00:00:40
+42,66.000177,-179.996665,2022/01/01,00:00:41
+43,66.000158,-179.997370,2022/01/01,00:00:42
+44,66.000130,-179.997675,2022/01/01,00:00:43
+45,66.000103,-179.997980,2022/01/01,00:00:44
+46,66.000104,-179.998505,2022/01/01,00:00:45
+47,66.000106,-179.999030,2022/01/01,00:00:46
+48,66.000082,-179.999295,2022/01/01,00:00:47
+49,66.000057,-179.999560,2022/01/01,00:00:48
+50,66.000050,179.999795,2022/01/01,00:00:49
+51,66.000042,179.999150,2022/01/01,00:00:50
+52,66.000096,179.998730,2022/01/01,00:00:51
+53,66.000150,179.998310,2022/01/01,00:00:52
+54,66.000172,179.997530,2022/01/01,00:00:53
+55,66.000193,179.996750,2022/01/01,00:00:54
+56,66.000160,179.996480,2022/01/01,00:00:55
+57,66.000128,179.996210,2022/01/01,00:00:56
+58,66.000110,179.995570,2022/01/01,00:00:57
+59,66.000091,179.994930,2022/01/01,00:00:58
+60,66.000141,179.994275,2022/01/01,00:00:59
+61,66.000191,179.993620,2022/01/01,00:01:00
+62,66.000124,179.993275,2022/01/01,00:01:01
+63,66.000057,179.992930,2022/01/01,00:01:02
+64,66.000077,179.992520,2022/01/01,00:01:03
+65,66.000098,179.992110,2022/01/01,00:01:04
+66,66.000069,179.991745,2022/01/01,00:01:05
+67,66.000040,179.991380,2022/01/01,00:01:06
+68,66.000077,179.990915,2022/01/01,00:01:07
+69,66.000114,179.990450,2022/01/01,00:01:08
+70,66.000096,179.989495,2022/01/01,00:01:09
+71,66.000077,179.988540,2022/01/01,00:01:10
+72,66.000045,179.988185,2022/01/01,00:01:11
+73,66.000013,179.987830,2022/01/01,00:01:12
+74,66.000095,179.987410,2022/01/01,00:01:13
+75,66.000176,179.986990,2022/01/01,00:01:14
+76,66.000098,179.986525,2022/01/01,00:01:15
+77,66.000021,179.986060,2022/01/01,00:01:16
+78,66.000057,179.985720,2022/01/01,00:01:17
+79,66.000093,179.985380,2022/01/01,00:01:18
+80,66.000146,179.984835,2022/01/01,00:01:19
+81,66.000199,179.984290,2022/01/01,00:01:20
+82,66.000192,179.983700,2022/01/01,00:01:21
+83,66.000184,179.983110,2022/01/01,00:01:22
+84,66.000153,179.982810,2022/01/01,00:01:23
+85,66.000122,179.982510,2022/01/01,00:01:24
+86,66.000112,179.982165,2022/01/01,00:01:25
+87,66.000102,179.981820,2022/01/01,00:01:26
+88,66.000124,179.981825,2022/01/01,00:01:27
+89,66.000147,179.981830,2022/01/01,00:01:28
+90,66.000109,179.981790,2022/01/01,00:01:29
+91,66.000071,179.981750,2022/01/01,00:01:30
+92,66.000072,179.981765,2022/01/01,00:01:31
+93,66.000073,179.981780,2022/01/01,00:01:32
+94,66.000120,179.981700,2022/01/01,00:01:33
+95,66.000167,179.981620,2022/01/01,00:01:34
diff --git a/reference/track/simint250m.csv b/reference/track/simint250m.csv
new file mode 100644
index 000000000..e42ca1297
--- /dev/null
+++ b/reference/track/simint250m.csv
@@ -0,0 +1,96 @@
+No,Latitude,Longitude,Date,Time
+1,66.000103,-179.979040,2022/01/01,00:00:00
+2,66.000146,-179.979035,2022/01/01,00:00:00.250
+3,66.000188,-179.979030,2022/01/01,00:00:00.500
+4,66.000106,-179.979250,2022/01/01,00:00:00.750
+5,66.000023,-179.979470,2022/01/01,00:00:01
+6,66.000034,-179.979775,2022/01/01,00:00:01.250
+7,66.000045,-179.980080,2022/01/01,00:00:01.500
+8,66.000111,-179.980280,2022/01/01,00:00:01.750
+9,66.000177,-179.980480,2022/01/01,00:00:02
+10,66.000143,-179.980575,2022/01/01,00:00:02.250
+11,66.000109,-179.980670,2022/01/01,00:00:02.500
+12,66.000138,-179.981320,2022/01/01,00:00:02.750
+13,66.000167,-179.981970,2022/01/01,00:00:03
+14,66.000121,-179.982585,2022/01/01,00:00:03.250
+15,66.000075,-179.983200,2022/01/01,00:00:03.500
+16,66.000105,-179.983745,2022/01/01,00:00:03.750
+17,66.000134,-179.984290,2022/01/01,00:00:04
+18,66.000128,-179.984740,2022/01/01,00:00:04.250
+19,66.000121,-179.985190,2022/01/01,00:00:04.500
+20,66.000159,-179.985385,2022/01/01,00:00:04.750
+21,66.000197,-179.985580,2022/01/01,00:00:05
+22,66.000177,-179.986145,2022/01/01,00:00:05.250
+23,66.000158,-179.986710,2022/01/01,00:00:05.500
+24,66.000148,-179.987380,2022/01/01,00:00:05.750
+25,66.000138,-179.988050,2022/01/01,00:00:06
+26,66.000154,-179.988555,2022/01/01,00:00:06.250
+27,66.000171,-179.989060,2022/01/01,00:00:06.500
+28,66.000111,-179.989380,2022/01/01,00:00:06.750
+29,66.000050,-179.989700,2022/01/01,00:00:07
+30,66.000058,-179.990500,2022/01/01,00:00:07.250
+31,66.000066,-179.991300,2022/01/01,00:00:07.500
+32,66.000056,-179.991565,2022/01/01,00:00:07.750
+33,66.000046,-179.991830,2022/01/01,00:00:08
+34,66.000089,-179.992615,2022/01/01,00:00:08.250
+35,66.000131,-179.993400,2022/01/01,00:00:08.500
+36,66.000110,-179.993620,2022/01/01,00:00:08.750
+37,66.000088,-179.993840,2022/01/01,00:00:09
+38,66.000127,-179.994440,2022/01/01,00:00:09.250
+39,66.000165,-179.995040,2022/01/01,00:00:09.500
+40,66.000180,-179.995500,2022/01/01,00:00:09.750
+41,66.000196,-179.995960,2022/01/01,00:00:10
+42,66.000177,-179.996665,2022/01/01,00:00:10.250
+43,66.000158,-179.997370,2022/01/01,00:00:10.500
+44,66.000130,-179.997675,2022/01/01,00:00:10.750
+45,66.000103,-179.997980,2022/01/01,00:00:11
+46,66.000104,-179.998505,2022/01/01,00:00:11.250
+47,66.000106,-179.999030,2022/01/01,00:00:11.500
+48,66.000082,-179.999295,2022/01/01,00:00:11.750
+49,66.000057,-179.999560,2022/01/01,00:00:12
+50,66.000050,179.999795,2022/01/01,00:00:12.250
+51,66.000042,179.999150,2022/01/01,00:00:12.500
+52,66.000096,179.998730,2022/01/01,00:00:12.750
+53,66.000150,179.998310,2022/01/01,00:00:13
+54,66.000172,179.997530,2022/01/01,00:00:13.250
+55,66.000193,179.996750,2022/01/01,00:00:13.500
+56,66.000160,179.996480,2022/01/01,00:00:13.750
+57,66.000128,179.996210,2022/01/01,00:00:14
+58,66.000110,179.995570,2022/01/01,00:00:14.250
+59,66.000091,179.994930,2022/01/01,00:00:14.500
+60,66.000141,179.994275,2022/01/01,00:00:14.750
+61,66.000191,179.993620,2022/01/01,00:00:15
+62,66.000124,179.993275,2022/01/01,00:00:15.250
+63,66.000057,179.992930,2022/01/01,00:00:15.500
+64,66.000077,179.992520,2022/01/01,00:00:15.750
+65,66.000098,179.992110,2022/01/01,00:00:16
+66,66.000069,179.991745,2022/01/01,00:00:16.250
+67,66.000040,179.991380,2022/01/01,00:00:16.500
+68,66.000077,179.990915,2022/01/01,00:00:16.750
+69,66.000114,179.990450,2022/01/01,00:00:17
+70,66.000096,179.989495,2022/01/01,00:00:17.250
+71,66.000077,179.988540,2022/01/01,00:00:17.500
+72,66.000045,179.988185,2022/01/01,00:00:17.750
+73,66.000013,179.987830,2022/01/01,00:00:18
+74,66.000095,179.987410,2022/01/01,00:00:18.250
+75,66.000176,179.986990,2022/01/01,00:00:18.500
+76,66.000098,179.986525,2022/01/01,00:00:18.750
+77,66.000021,179.986060,2022/01/01,00:00:19
+78,66.000057,179.985720,2022/01/01,00:00:19.250
+79,66.000093,179.985380,2022/01/01,00:00:19.500
+80,66.000146,179.984835,2022/01/01,00:00:19.750
+81,66.000199,179.984290,2022/01/01,00:00:20
+82,66.000192,179.983700,2022/01/01,00:00:20.250
+83,66.000184,179.983110,2022/01/01,00:00:20.500
+84,66.000153,179.982810,2022/01/01,00:00:20.750
+85,66.000122,179.982510,2022/01/01,00:00:21
+86,66.000112,179.982165,2022/01/01,00:00:21.250
+87,66.000102,179.981820,2022/01/01,00:00:21.500
+88,66.000124,179.981825,2022/01/01,00:00:21.750
+89,66.000147,179.981830,2022/01/01,00:00:22
+90,66.000109,179.981790,2022/01/01,00:00:22.250
+91,66.000071,179.981750,2022/01/01,00:00:22.500
+92,66.000072,179.981765,2022/01/01,00:00:22.750
+93,66.000073,179.981780,2022/01/01,00:00:23
+94,66.000120,179.981700,2022/01/01,00:00:23.250
+95,66.000167,179.981620,2022/01/01,00:00:23.500
diff --git a/testo.d/track.test b/testo.d/track.test
index 90aea72d9..cc1de5874 100644
--- a/testo.d/track.test
+++ b/testo.d/track.test
@@ -65,3 +65,13 @@ compare ${REFERENCE}/track/trackfilter_trk2seg~gpx.gpx ${TMPDIR}/trackfilter_trk
 # speed with msec
 gpsbabel -t -i unicsv -f ${REFERENCE}/track/utm_subsecond_track.csv -x track,speed -o unicsv,utc -F ${TMPDIR}/utm_subsecond_track~csv.csv
 compare ${REFERENCE}/track/utm_subsecond_track~csv.csv ${TMPDIR}/utm_subsecond_track~csv.csv
+
+# faketime, with and witout partial second steps
+gpsbabel -t -i unicsv -f ${REFERENCE}/track/simint.csv -x track,faketime=f2022+0.25 -o unicsv,utc -F ${TMPDIR}/simint250m.csv
+compare ${REFERENCE}/track/simint250m.csv ${TMPDIR}/simint250m.csv
+gpsbabel -t -i unicsv -f ${REFERENCE}/track/simint.csv -x track,faketime=f2022+.25 -o unicsv,utc -F ${TMPDIR}/simint250m_2.csv
+compare ${REFERENCE}/track/simint250m.csv ${TMPDIR}/simint250m_2.csv
+gpsbabel -t -i unicsv -f ${REFERENCE}/track/simint.csv -x track,faketime=f2022+1 -o unicsv,utc -F ${TMPDIR}/simint1000m.csv
+compare ${REFERENCE}/track/simint1000m.csv ${TMPDIR}/simint1000m.csv
+
+
diff --git a/trackfilter.cc b/trackfilter.cc
index 2df3efb6f..d157249b2 100644
--- a/trackfilter.cc
+++ b/trackfilter.cc
@@ -826,7 +826,7 @@ TrackFilter::faketime_t TrackFilter::trackfilter_faketime_check(const char* time
 {
   faketime_t result;
 
-  static const QRegularExpression re(R"(^(f?)(\d{0,14})(?:\+(\d{1,10}))?$)");
+  static const QRegularExpression re(R"(^(f?)(\d{0,14})(?:\+(\d+(?:\.\d*)?|\.\d+))?$)");
   assert(re.isValid());
   QRegularExpressionMatch match = re.match(timestr);
   if (match.hasMatch()) {
@@ -843,7 +843,7 @@ TrackFilter::faketime_t TrackFilter::trackfilter_faketime_check(const char* time
 
     if (match.capturedLength(3) > 0) {
       bool ok;
-      result.step = match.captured(3).toInt(&ok);
+      result.step = llround(1000.0 * match.captured(3).toDouble(&ok));
       if (!ok) {
         fatal(MYNAME "-faketime-check: Invalid step \"%s\"!\n", qPrintable(match.captured(3)));
       }
@@ -852,7 +852,7 @@ TrackFilter::faketime_t TrackFilter::trackfilter_faketime_check(const char* time
     }
 
 #ifdef TRACKF_DBG
-    qDebug() << MYNAME "-faketime option: force =" << result.force << ", timestamp =" << result.start << ", step =" << result.step;
+    qDebug() << MYNAME "-faketime option: force =" << result.force << ", timestamp =" << result.start << ", step =" << result.step << "milliseconds";
 #endif
   } else {
     fatal(MYNAME "-faketime-check: Invalid value for faketime option \"%s\"!\n", timestr);
@@ -871,7 +871,7 @@ void TrackFilter::trackfilter_faketime()
 
       if (!wpt->creation_time.isValid() || faketime.force) {
         wpt->creation_time = faketime.start;
-        faketime.start = faketime.start.addSecs(faketime.step);
+        faketime.start = faketime.start.addMSecs(faketime.step);
       }
     }
   }
diff --git a/trackfilter.h b/trackfilter.h
index 13d04669e..c76add21b 100644
--- a/trackfilter.h
+++ b/trackfilter.h
@@ -212,7 +212,7 @@ class TrackFilter:public Filter
 
   struct faketime_t {
     QDateTime start;
-    int    step{0};
+    long long step{0};
     bool   force{false};
   };