diff --git a/gemsupervisor/src/GEMSupervisor.cpp b/gemsupervisor/src/GEMSupervisor.cpp
index 4b21b3e31e20cbf3f9700ba3b9ffbe0dcfb693b9..dfc3f23c3eae521c02c266570b2281a42a877325 100644
--- a/gemsupervisor/src/GEMSupervisor.cpp
+++ b/gemsupervisor/src/GEMSupervisor.cpp
@@ -885,7 +885,7 @@ uint64_t gem::supervisor::GEMSupervisor::getNewLocalRunNumber()
 
     uint32_t localRunNumber = 2'000'000'000; // First era
     localRunNumber += ((now.tm_year - 100) * 365 + now.tm_yday - 1) * 100'000; // Epoch on 1 January 2000 00:00:00 UTC
-    localRunNumber += now.tm_hour + 3600 + now.tm_min * 60 + now.tm_sec;
+    localRunNumber += now.tm_hour * 3600 + now.tm_min * 60 + now.tm_sec;
 
     for (;; ++localRunNumber) {
         if (std::filesystem::create_directories(m_outputPath.value_ + "/run" + runNumberToString(localRunNumber, true)))