diff --git a/src/core/config/OperationConfig.js b/src/core/config/OperationConfig.js
index 346ca6a7..7472e93f 100755
--- a/src/core/config/OperationConfig.js
+++ b/src/core/config/OperationConfig.js
@@ -2261,19 +2261,31 @@ const OperationConfig = {
             }
         ]
     },
-    "From Windows Filetime To UNIX":{
+    "Windows Filetime to UNIX Timestamp":{
         description: "Converts a Windows Filetime timestamp to a datetime format",
         run: DateTime.runFromFiletimeToUnix,
         inputType: "string",
         outputType: "string",
-        args: []
+        args: [
+            {
+                name: "Units",
+                type: "Option",
+                value: DateTime.UNITS
+            }
+        ]
     },
-    "To Windows Filetime From UNIX":{
+    "UNIX Timestamp to Windows Filetime":{
         description: "Parses a datetime string in UTC and returns the corresponding Windows Filetime timestamp",
         run: DateTime.runToFiletimeFromUnix,
         inputType: "string",
         outputType: "string",
-        args: []
+        args: [
+            {
+                name: "Units",
+                type: "Option",
+                value: DateTime.UNITS
+            }
+        ]
     },
     "Translate DateTime Format": {
         description: "Parses a datetime string in one format and re-writes it in another.<br><br>Run with no input to see the relevant format string examples.",
diff --git a/src/core/operations/DateTime.js b/src/core/operations/DateTime.js
index f3c90241..c9d9645d 100755
--- a/src/core/operations/DateTime.js
+++ b/src/core/operations/DateTime.js
@@ -1,4 +1,6 @@
-import Decimal from "../lib/decimal.min.js";
+//import Decimal from "../lib/decimal.min.js";
+import Utils from "../Utils.js";
+import {BigInteger} from "jsbn";
 
 /**
  * Date and time operations.
@@ -83,35 +85,52 @@ const DateTime = {
     /**
      * Converts a Windows FILETIME to Unix Epoch time.
      *
+     * @author bwhitn [brian.m.whitney@outlook.com]
      * @param {string} input
      * @param {Object[]} args (not used)
      * @returns {string}
      */
     runFromFiletimeToUnix: function(input, args) {
-        input = new Decimal(input);
-        input = input.sub(116444736000000000).div(10000000);
-        if (input.gte(0) && input.lt(Math.pow(2, 31))){
-            return input.toString();
+        let units = args[0], offset = new BigInteger("116444736000000000");
+        input = new BigInteger(input,16).subtract(offset);
+        if (units === "Seconds (s)"){
+            input = input.divide(new BigInteger("10000000"));
+        } else if (units === "Milliseconds (ms)") {
+            input = input.divide(new BigInteger("10000"));
+        } else if (units === "Microseconds (μs)") {
+            input = input.divide(new BigInteger("10"));
+        } else if (units === "Nanoseconds (ns)") {
+            input = input.multiply(new BigInteger("100"));
         } else {
-            throw "Date " + input + " is not a valid date";
+            throw "The value " + input + " cannot be expressed as a UNIX timestamp.";
         }
+        return input.toString();
     },
 
 
     /**
      * Converts a Unix Epoch time to Windows FILETIME.
      *
+     * @author bwhitn [brian.m.whitney@outlook.com]
      * @param {string} input
      * @param {Object[]} args (not used)
      * @returns {string}
      */
     runToFiletimeFromUnix: function(input, args) {
-        input = new Decimal(input);
-        if (input.gte(0) && input.lt(Math.pow(2, 31))){
-            return input.mul(10000000).add(116444736000000000).toHex();
+        let units = args[0], offset = new BigInteger("116444736000000000");
+        input = new BigInteger(input);
+        if (units === "Seconds (s)"){
+            input = input.multiply(new BigInteger("10000000")).add(offset);
+        } else if (units === "Milliseconds (ms)") {
+            input = input.multiply(new BigInteger("10000")).add(offset);
+        } else if (units === "Microseconds (μs)") {
+            input = input.multiply(new BigInteger("10")).add(offset);
+        } else if (units === "Nanoseconds (ns)") {
+            input = input.divide(new BigInteger("100")).add(offset);
         } else {
-            throw "Date " + input + " is not a valid date";
+            throw "The value " + input + " cannot be expressed as a UNIX timestamp.";
         }
+        return input.toString();
     },