diff --git a/lib/nn.js b/lib/nn.js
index 9461679..f0f607f 100644
--- a/lib/nn.js
+++ b/lib/nn.js
@@ -6,6 +6,8 @@ var DEFAULT_OPTS = {
     layers: [ 3 ],
     // maximum training epochs to perform on the training data
     iterations: 20000,
+    // maximum execution time, in seconds
+    time: Infinity,
     // minimum acceptable error threshold
     errorThresh: 0.0005,
     // activation function ('logistic' and 'hyperbolic' supported)
@@ -69,8 +71,9 @@ NN.prototype.train = function (trainingData) {
     var iterations = this.opts.iterations
     var totalIterations = 0
     var mse = 1
+    var startTime = new Date()
 
-    while (totalIterations++ < iterations && mse > this.opts.errorThresh) {
+    while (totalIterations++ < iterations && mse > this.opts.errorThresh && (new Date() - startTime)/1000 < this.opts.time) {
 
         // run through the training data
         trainingData.forEach(function (trainingEntry, index) {