Replaced calls to DateTime.Now with DateTime.UtcNow to be locale agnostic (#133)

* Removed calls to DateTime.Now

The codebase now uses DateTime.UtcNow, instead of DateTime.Now, to be locale agnostic, except in cases where timezone info is actually needed. Also replaced one starttime measurement with stopwatch.

Author: Sorrien

src/Microsoft.ML.Core/Data/ProgressReporter.cs

@@ -359,7 +359,7 @@ public CalculationInfo(int index, string name, ProgressChannel channel)
                     Index = index;
                     Name = name;
                     PendingCheckpoints = new ConcurrentQueue<KeyValuePair<DateTime, ProgressEntry>>();
-                    StartTime = DateTime.Now;
+                    StartTime = DateTime.UtcNow;
                     Channel = channel;
                 }
             }
@@ -584,7 +584,7 @@ public ProgressEvent(int index, string name, DateTime startTime, ProgressEntry e
                 Index = index;
                 Name = name;
                 StartTime = startTime;
-                EventTime = DateTime.Now;
+                EventTime = DateTime.UtcNow;
                 Kind = EventKind.Progress;
                 ProgressEntry = entry;
             }
@@ -597,7 +597,7 @@ public ProgressEvent(int index, string name, DateTime startTime, EventKind kind)
                 Index = index;
                 Name = name;
                 StartTime = startTime;
-                EventTime = DateTime.Now;
+                EventTime = DateTime.UtcNow;
                 Kind = kind;
                 ProgressEntry = null;
             }

src/Microsoft.ML.Data/Utilities/TimerScope.cs

@@ -46,7 +46,7 @@ public void Dispose()
 
             // REVIEW: This is \n\n is to prevent changes across bunch of baseline files.
             // Ideally we should change our comparison method to ignore empty lines.
-            _ch.Info("{0}\t Time elapsed(s): {1}\n\n", DateTime.Now, elapsedSeconds);
+            _ch.Info("{0}\t Time elapsed(s): {1}\n\n", DateTime.UtcNow, elapsedSeconds);
 
             using (var pipe = _host.StartPipe<TelemetryMessage>("TelemetryPipe"))
             {

src/Microsoft.ML.FastTree/Training/EnsembleCompression/LassoBasedEnsembleCompressor.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 
 namespace Microsoft.ML.Runtime.FastTree.Internal
 {
@@ -164,7 +165,7 @@ public unsafe void SetTreeScores(int idx, double[] scores)
 
         private LassoFit GetLassoFit(IChannel ch, int maxAllowedFeaturesPerModel)
         {
-            DateTime startTime = DateTime.Now;
+            Stopwatch stopWatch = Stopwatch.StartNew();
 
             if (maxAllowedFeaturesPerModel < 0)
             {
@@ -450,8 +451,8 @@ private LassoFit GetLassoFit(IChannel ch, int maxAllowedFeaturesPerModel)
             // First lambda was infinity; fixing it
             fit.Lambdas[0] = Math.Exp(2 * Math.Log(fit.Lambdas[1]) - Math.Log(fit.Lambdas[2]));
 
-            TimeSpan duration = DateTime.Now - startTime;
-            ch.Info("Elapsed time for compression: {0}", duration);
+            stopWatch.Stop();
+            ch.Info("Elapsed time for compression: {0}", stopWatch.Elapsed);
 
             return fit;
         }

src/Microsoft.ML.FastTree/TreeEnsemble/Ensemble.cs

@@ -193,7 +193,7 @@ public string ToTreeEnsembleIni(FeaturesToContentMap fmap,
 
         protected int AppendComments(StringBuilder sb, string trainingParams)
         {
-            sb.AppendFormat("\n\n[Comments]\nC:0=Regression Tree Ensemble\nC:1=Generated using FastTree\nC:2=Created on {0}\n", DateTime.Now);
+            sb.AppendFormat("\n\n[Comments]\nC:0=Regression Tree Ensemble\nC:1=Generated using FastTree\nC:2=Created on {0}\n", DateTime.UtcNow);
 
             string[] trainingParamsList = trainingParams.Split(new char[] { '\n' });
             int i = 0;

src/Microsoft.ML.Maml/MAML.cs

@@ -145,7 +145,7 @@ internal static int MainCore(TlcEnvironment env, string args, bool alwaysPrintSt
                         Path.GetTempPath(),
                         "TLC");
                     var dumpFilePath = Path.Combine(dumpFileDir,
-                        string.Format(CultureInfo.InvariantCulture, "Error_{0:yyyyMMdd_HHmmss}_{1}.log", DateTime.Now, Guid.NewGuid()));
+                        string.Format(CultureInfo.InvariantCulture, "Error_{0:yyyyMMdd_HHmmss}_{1}.log", DateTime.UtcNow, Guid.NewGuid()));
                     bool isDumpSaved = false;
                     try
                     {

src/Microsoft.ML.ResultProcessor/ResultProcessor.cs

@@ -584,7 +584,7 @@ private static bool ValidateMamlOutput(string filename, string[] rawLines, out L
                 Results = runResults,
                 PerFoldResults = foldResults,
                 Time = 0,
-                ExecutionDate = DateTime.Now.ToString()
+                ExecutionDate = DateTime.UtcNow.ToString()
             };
         }
 

src/Microsoft.ML.StandardLearners/Standard/Online/OnlineLinear.cs

@@ -206,7 +206,7 @@ protected virtual void InitCore(IChannel ch, int numFeatures, LinearPredictor pr
             Contracts.Assert(Iteration == 0);
             Contracts.Assert(Bias == 0);
 
-            ch.Trace("{0} Initializing {1} on {2} features", DateTime.Now, Name, numFeatures);
+            ch.Trace("{0} Initializing {1} on {2} features", DateTime.UtcNow, Name, numFeatures);
             NumFeatures = numFeatures;
 
             // We want a dense vector, to prevent memory creation during training
@@ -253,13 +253,13 @@ protected virtual void BeginIteration(IChannel ch)
             Iteration++;
             NumIterExamples = 0;
 
-            ch.Trace("{0} Starting training iteration {1}", DateTime.Now, Iteration);
+            ch.Trace("{0} Starting training iteration {1}", DateTime.UtcNow, Iteration);
             // #if OLD_TRACING // REVIEW: How should this be ported?
             if (Iteration % 20 == 0)
             {
                 Console.Write('.');
                 if (Iteration % 1000 == 0)
-                    Console.WriteLine(" {0}  \t{1}", Iteration, DateTime.Now);
+                    Console.WriteLine(" {0}  \t{1}", Iteration, DateTime.UtcNow);
             }
             // #endif
         }
@@ -269,7 +269,7 @@ protected virtual void FinishIteration(IChannel ch)
             Contracts.Check(NumIterExamples > 0, NoTrainingInstancesMessage);
 
             ch.Trace("{0} Finished training iteration {1}; iterated over {2} examples.",
-                DateTime.Now, Iteration, NumIterExamples);
+                DateTime.UtcNow, Iteration, NumIterExamples);
 
             ScaleWeights();
 #if OLD_TRACING // REVIEW: How should this be ported?
@@ -378,7 +378,7 @@ protected virtual void ProcessDataInstance(IChannel ch, ref VBuffer<Float> feat,
                         if (_numIterExamples % 5000000 == 0)
                         {
                             Host.StdOut.Write(" ");
-                            Host.StdOut.Write(DateTime.Now);
+                            Host.StdOut.Write(DateTime.UtcNow);
                         }
                         Host.StdOut.WriteLine();
                     }