3 files changed, 8 insertions, 0 deletions
diff --git a/src/buildtool/main/main.cpp b/src/buildtool/main/main.cpp
index 10abfa1a..3da6de93 100644
--- a/src/buildtool/main/main.cpp
+++ b/src/buildtool/main/main.cpp
@@ -1244,6 +1244,9 @@ auto main(int argc, char* argv[]) -> int {
                 analyse_result->id.ToShortString(
                     Evaluator::GetExpressionLogLimit()));
 
+            if (profile != nullptr) {
+                profile->StartBuild();
+            }
             auto build_result =
                 traverser.BuildAndStage(artifacts,
                                         runfiles,
diff --git a/src/buildtool/profile/profile.cpp b/src/buildtool/profile/profile.cpp
index 5ee9cd15..1d8a7b46 100644
--- a/src/buildtool/profile/profile.cpp
+++ b/src/buildtool/profile/profile.cpp
@@ -178,3 +178,7 @@ void Profile::SetRemoteExecutionConfig(RemoteExecutionConfig const& config) {
     remote["dispatch"] = dispatch;
     profile_["remote"] = remote;
 }
+
+void Profile::StartBuild() {
+    profile_["build start time"] = std::time(nullptr);
+}
diff --git a/src/buildtool/profile/profile.hpp b/src/buildtool/profile/profile.hpp
index 0db655fb..099ce2cc 100644
--- a/src/buildtool/profile/profile.hpp
+++ b/src/buildtool/profile/profile.hpp
@@ -46,6 +46,7 @@ class Profile {
                              IExecutionResponse::Ptr const& response,
                              std::string const& cwd);
     void NoteAnalysisError(std::string const& error_message);
+    void StartBuild();
 
   private:
     struct ActionData {