diff --git a/datetime.c b/datetime.c
index aa23d53..b0644ba 100644
--- a/datetime.c
+++ b/datetime.c
@@ -32,6 +32,7 @@
 
 #include "epoch.h"
 #include <stdint.h>
+#include <stdio.h>
 #include <time.h>
 
 int32_t dateTimeGetYear(DateTime *self) {
@@ -84,21 +85,20 @@ Weekday dateTimeGetWeekday(DateTime *self) {
 }
 
 void dateTimeFromTimestampParts(int64_t seconds, int64_t nanoseconds, DateTime *dt) {
-    int64_t secs;
     int     ret = 0;
     
     dt->nanoseconds = nanoseconds;
+    dt->zone.tag = UTC;
     if (seconds < 0) {
-        secs = seconds;
         yearNew(&dt->year, 1969);
-        while (secs < yearGetSeconds(&dt->year)) {
-            secs += yearGetSeconds(&dt->year);
+        while (seconds < yearGetSeconds(&dt->year)) {
+            seconds += yearGetSeconds(&dt->year);
             yearDecrement(&dt->year);
         }
         dt->month = December;
         while (ret == 0) {
-            if (-secs < monthGetSeconds(dt->month, &dt->year)) break;
-            secs += monthGetSeconds(dt->month, &dt->year);
+            if (-seconds < monthGetSeconds(dt->month, &dt->year)) break;
+            seconds += monthGetSeconds(dt->month, &dt->year);
             ret = monthDecrement(&dt->month);
         }
         ret = 0;
@@ -119,24 +119,23 @@ void dateTimeFromTimestampParts(int64_t seconds, int64_t nanoseconds, DateTime *
         }
         dt->second = seconds + 60;
     } else if (seconds > 0) {
-        secs = seconds;
         yearNew(&dt->year, 1970);
         while (yearGetSeconds(&dt->year) < seconds) {
-            secs -= yearGetSeconds(&dt->year);
+            seconds -= yearGetSeconds(&dt->year);
             yearIncrement(&dt->year);
         }
         dt->month = January;
-        while (ret == 0 && monthGetSeconds(dt->month, &dt->year) < secs) {
-            secs -= (int64_t)monthGetSeconds(dt->month, &dt->year);
+        while (ret == 0 && monthGetSeconds(dt->month, &dt->year) < seconds) {
+            seconds -= (int64_t)monthGetSeconds(dt->month, &dt->year);
             ret = monthIncrement(&dt->month);
         }
-        dt->day = secs / SECONDS_PER_DAY;
-        secs %= SECONDS_PER_DAY;
-        dt->hour = secs / SECONDS_PER_HOUR;
-        secs %= SECONDS_PER_HOUR;
-        dt->minute = secs / 60;
-        secs %= 60;
-        dt->second = secs;
+        dt->day = seconds / SECONDS_PER_DAY + 1;
+        seconds %= SECONDS_PER_DAY;
+        dt->hour = seconds / SECONDS_PER_HOUR;
+        seconds %= SECONDS_PER_HOUR;
+        dt->minute = seconds / 60;
+        seconds %= 60;
+        dt->second = seconds;
     } else {
         yearNew(&dt->year, 1970);
         dt->month = January;
diff --git a/include/epoch.h b/include/epoch.h
index 581c191..f73d61d 100644
--- a/include/epoch.h
+++ b/include/epoch.h
@@ -37,8 +37,8 @@
 #include <time.h>
 
 #define SECONDS_PER_MINUTE 60
-#define SECONDS_PER_HOUR   60 * 60
-#define SECONDS_PER_DAY    60 * 60 * 24
+#define SECONDS_PER_HOUR   3600
+#define SECONDS_PER_DAY    86400
 
 typedef enum {
     normalYear,
diff --git a/test/Makefile b/test/Makefile
index 1d99955..0caba5f 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -38,6 +38,7 @@ LDLIBS     += $(LIBS)
 
 tests      += dt2ts
 tests      += dt2timespec
+tests      += dtfromtimespec
 tests      += parsemonth
 
 total      != echo $(tests) | wc -w | awk '{ print $$1 }'
diff --git a/test/dtfromtimespec.c b/test/dtfromtimespec.c
new file mode 100644
index 0000000..49fdade
--- /dev/null
+++ b/test/dtfromtimespec.c
@@ -0,0 +1,21 @@
+#include "epoch.h"
+#include <assert.h>
+#include <time.h>
+
+int main() {
+    struct timespec ts;
+    DateTime dt;
+
+    ts.tv_nsec = 42;
+    ts.tv_sec  = 1706571482;
+    dateTimeFromTimespec(&ts, &dt);
+    assert(dt.year.year == 2024);
+    assert(dt.month == January);
+    assert(dt.day == 29);
+    assert(dt.hour == 23);
+    assert(dt.minute == 38);
+    assert(dt.second == 02);
+    assert(dt.nanoseconds == 42);
+    assert(dt.zone.tag == UTC);
+    return 0;
+}