diff --git a/models/file.js b/models/file.js
index 949d83b3ec0010af5ae43335a9ba32e7b655e2c5..dd3a5d14bde2167f4e4a622fee4c44d69b9bf798 100644
--- a/models/file.js
+++ b/models/file.js
@@ -33,6 +33,6 @@ var fileSchema = new Schema({
   dimensions: { type: Schema.Types.Mixed },
   user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
   date: { type: Date, default: Date.now }
-}, { versionKey: false });
+}, { versionKey: false, timestamps: true });
 
 module.exports = mongoose.model('File', fileSchema);
diff --git a/models/project.js b/models/project.js
index f75e490763d22c3ba91289cd19bcd6575c48cf76..0e135c539edecf2a03a05f3d798c6d093eed1cda 100644
--- a/models/project.js
+++ b/models/project.js
@@ -33,7 +33,7 @@ var projectSchema = new Schema({
   user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
   visualizations: [{ type: Schema.Types.ObjectId, ref: 'Visualization', default: [] }],
   simulation: { type: Schema.Types.ObjectId, ref: 'Simulation', required: true }
-}, { versionKey: false });
+}, { versionKey: false, timestamps: true });
 
 projectSchema.pre('remove', function(callback) {
   // delete all visualizations belonging to this project
diff --git a/models/simulationModel.js b/models/simulationModel.js
index 8cba8789121d084718f64e227a89da655b1a2364..d94fb99413cf91ab14c276a13cd1b0dbfc7fa9b2 100644
--- a/models/simulationModel.js
+++ b/models/simulationModel.js
@@ -30,6 +30,6 @@ const simulationModelSchema = new mongoose.Schema({
     outputMapping: { type: mongoose.Schema.Types.Mixed, default: {} },
     inputMapping: { type: mongoose.Schema.Types.Mixed, default: {} },
     startParameters: { type: mongoose.Schema.Types.Mixed, default: {} }
-}, { versionKey: false });
+}, { versionKey: false, timestamps: true });
 
 module.exports = mongoose.model('SimulationModel', simulationModelSchema);
diff --git a/models/user.js b/models/user.js
index aff470c6107ce77a2b24f96c057fb2351d93c767..3065d0efb26c92b85aa37bb489259ad35da3a517 100644
--- a/models/user.js
+++ b/models/user.js
@@ -38,7 +38,7 @@ var userSchema = new Schema({
   mail: { type: String, default: "" },
   simulations: [{ type: Schema.Types.ObjectId, ref: 'Simulation', default: [] }],
   files: [{type: Schema.Types.ObjectId, ref: 'File', default: [] }]
-}, { versionKey: false });
+}, { versionKey: false, timestamps: true });
 
 userSchema.methods.verifyPassword = function(password, callback) {
   bcrypt.compare(password, this.password, function(err, isMatch) {
diff --git a/models/visualization.js b/models/visualization.js
index 53d42e1c08836529d68d9912a32ba4b97683e969..ea68e21f6caeb4a1b194655b40e0a02aedc8a9cf 100644
--- a/models/visualization.js
+++ b/models/visualization.js
@@ -31,6 +31,6 @@ var visualizationSchema = new Schema({
   widgets: { type: Array, default: [] },
   grid: { type: Number, default: 1 },
   user: { type: Schema.Types.ObjectId, ref: 'User', required: true }
-}, { versionKey: false });
+}, { versionKey: false, timestamps: true });
 
 module.exports = mongoose.model('Visualization', visualizationSchema);