diff --git a/README.md b/README.md
index 9e5e751..ceca978 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ chronoparse parses the given string, and returns an object using the following s
 ```js
 {
     totalSeconds, // an integer representing the total length of the timespan in seconds
-    startDate, // the current datetime as of parsing completion
+    startDate, // the given startDate in the options object
     endDate, // a datetime totalSeconds from startDate
     timezone, // the current local timezone, specified as "UTC+/-X" where X is the offset in hours
     parts // an array of each timespan string parsed
@@ -50,6 +50,7 @@ The options object may contain any or all of the following options:
 ```js
 {
     delimiter, // a string to use to separate multiple timespans, defaults to whitespace
+    startDate, // a Date object specifying when to calculate datetimes from, defaults to now
     max // a non-negative integer specifying the maximum number of timespans to parse in the string, defaults to no limit
 }
 ```
diff --git a/src/index.js b/src/index.js
index b8e30fb..2271582 100644
--- a/src/index.js
+++ b/src/index.js
@@ -73,9 +73,9 @@ module.exports = function parse(text, options = {}) {
         outputData.parts += res[0];
     }
 
-    let date = new Date();
+    let date = options.startDate || new Date();
     date.setSeconds(date.getSeconds() + outputData.totalSeconds);
-    outputData.startDate = new Date();
+    outputData.startDate = options.startDate || new Date();
     outputData.endDate = date;
     outputData.timezone = getTimezone();
 
diff --git a/test/chronoparse.text.js b/test/chronoparse.text.js
index 0809906..899198a 100644
--- a/test/chronoparse.text.js
+++ b/test/chronoparse.text.js
@@ -113,4 +113,26 @@ describe("parse", function() {
         tzMock.register("UTC");
         expect(parse("1 second").timezone).to.equal("UTC+0");
     });
+
+    it ("should return the date of completion as the startDate", function() {
+        let now = new Date();
+        let result = parse("29 seconds").startDate;
+        // Will fail if parsing takes more than 60 seconds
+        expect(result - now).to.be.lessThan(60000);
+    });
+
+    it ("should return an endDate that matches the given timespan", function() {
+        let result = parse("29 seconds");
+        expect(result.endDate - result.startDate).to.equal(29000);
+    });
+
+    it ("should support specifying a different startDate", function() {
+        let date = new Date();
+        date.setSeconds(date.getSeconds() + 120);
+        let endDate = new Date();
+        endDate.setSeconds(endDate.getSeconds() + 149);
+        let result = parse("29 seconds", {startDate: date});
+        expect(result.startDate.toString()).to.equal(date.toString());
+        expect(result.endDate.toString()).to.equal(endDate.toString());
+    });
 });
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