diff --git a/lib/protocol/Writer.js b/lib/protocol/Writer.js
index 28cf501..fd26013 100644
--- a/lib/protocol/Writer.js
+++ b/lib/protocol/Writer.js
@@ -861,7 +861,7 @@ Writer.prototype[TypeCode.LONGDATE] = function writeLongDate(value) {
     hours = ~~ts[4];
     minutes = ~~ts[5];
     seconds = ~~ts[6];
-    nanoseconds = ~~((ts[6] * 1000000000) % 1000000000);
+    nanoseconds = ~~((ts[6] * 10000000) % 10000000);
   } else {
     throw createInputError('LONGDATE');
   }
@@ -877,7 +877,7 @@ Writer.prototype[TypeCode.LONGDATE] = function writeLongDate(value) {
   }
   const dayDate = calendar.DAYDATE(year, month, day);
   const dayFactor = BigInt(10000000) * BigInt(60 * 60 * 24);
-  const timeValue = BigInt(((hours * 60) + minutes) * 60 + seconds) * BigInt(10000000) + BigInt(~~(nanoseconds / 100));
+  const timeValue = BigInt(((hours * 60) + minutes) * 60 + seconds) * BigInt(10000000) + BigInt(nanoseconds);
   const longDate = BigInt(dayDate - 1) * dayFactor + timeValue + BigInt(1);
   var buffer = new Buffer(9);
   buffer[0] = TypeCode.LONGDATE;