diff --git a/src/studio/kdb/K.java b/src/studio/kdb/K.java
index 2e648e8..547d928 100755
--- a/src/studio/kdb/K.java
+++ b/src/studio/kdb/K.java
@@ -1068,7 +1068,7 @@ public StringBuilder format(StringBuilder builder, KFormatContext context) {
         }
 
         public Timestamp toTimestamp() {
-            return new Timestamp(((long) (.5 + 8.64e7 * (value + 10957))));
+            return new Timestamp(Math.round(8.64e7 * (value + 10957)));
         }
     }
 
@@ -1415,7 +1415,7 @@ public static KTimespan duration(double duration, KType unitType) {
             if (! NS_IN_TYPES.containsKey(unitType))
                 throw new IllegalArgumentException(unitType.toString() + " is not supported");
 
-            return new KTimespan((long) (duration * NS_IN_TYPES.get(unitType)));
+            return new KTimespan(Math.round (duration * NS_IN_TYPES.get(unitType)));
         }
 
         public double toUnitValue(KType unitType) {
@@ -1429,7 +1429,7 @@ public static KTimespan duration(double duration, ChronoUnit unit) {
             if (! NS_IN_UNITS.containsKey(unit))
                 throw new IllegalArgumentException("Unit " + unit.toString() + " is not supported");
 
-            return new KTimespan((long) (duration * NS_IN_UNITS.get(unit)) );
+            return new KTimespan(Math.round (duration * NS_IN_UNITS.get(unit)) );
 
         }
 
diff --git a/src/studio/kdb/KFormat.java b/src/studio/kdb/KFormat.java
index a3bb25a..0c869ee 100644
--- a/src/studio/kdb/KFormat.java
+++ b/src/studio/kdb/KFormat.java
@@ -6,7 +6,6 @@
 import java.text.ParsePosition;
 import java.time.Duration;
 import java.time.LocalDateTime;
-import java.time.temporal.ChronoUnit;
 
 public class KFormat extends NumberFormat {
 
@@ -58,7 +57,7 @@ public StringBuffer format(double value, StringBuffer toAppendTo, FieldPosition
                 if (hasFraction) {
                     LocalDateTime dateTime = ((K.Month)kValue).toLocalDateTime();
 
-                    LocalDateTime next = dateTime.plus((int)Math.signum(fraction), ChronoUnit.MONTHS);
+                    LocalDateTime next = dateTime.plusMonths((int)Math.signum(fraction));
                     long days = Duration.between(dateTime, next).toDays();
                     long ns = (long) (Math.abs(fraction) * days * K.NS_IN_DAY);
                     kValue = K.KTimestamp.of(dateTime).add(new K.KTimespan(ns));
diff --git a/test/studio/kdb/KTest.java b/test/studio/kdb/KTest.java
index b964578..604dc56 100644
--- a/test/studio/kdb/KTest.java
+++ b/test/studio/kdb/KTest.java
@@ -284,7 +284,7 @@ public void testSecondToString() throws Exception {
 
     @Test
     public void testDatetimeToString() throws Exception {
-        check(new K.KDatetime(-123456.789), "1661.12.26T05:03:50.401", "1661.12.26T05:03:50.401");
+        check(new K.KDatetime(-123456.789), "1661.12.26T05:03:50.400", "1661.12.26T05:03:50.400");
         check(new K.KDatetime(123.456), "2000.05.03T10:56:38.400", "2000.05.03T10:56:38.400");
         check(new K.KDatetime(Double.NEGATIVE_INFINITY), "-0wz", "-0wz");
         check(new K.KDatetime(Double.POSITIVE_INFINITY), "0wz", "0wz");