diff --git a/libs/indibase/indiccd.cpp b/libs/indibase/indiccd.cpp
index bdfa1dc0ae..c39ca4a60b 100644
--- a/libs/indibase/indiccd.cpp
+++ b/libs/indibase/indiccd.cpp
@@ -47,6 +47,7 @@
 #include <libnova/ln_types.h>
 #include <libastro.h>
 
+#include <iomanip>
 #include <cmath>
 #include <regex>
 #include <iterator>
@@ -2543,14 +2544,18 @@ bool CCD::uploadFile(CCDChip * targetChip, const void * fitsData, size_t totalBy
 
         if (maxIndex > 0)
         {
-            char ts[32];
-            struct tm * tp;
-            time_t t;
-            time(&t);
-            tp = localtime(&t);
-            strftime(ts, sizeof(ts), "%Y-%m-%dT%H-%M-%S", tp);
-            std::string filets(ts);
-            prefix = std::regex_replace(prefix, std::regex("ISO8601"), filets);
+            auto now = std::chrono::system_clock::now();
+            std::time_t time = std::chrono::system_clock::to_time_t(now);
+            std::tm* now_tm = std::localtime(&time);
+            long long timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
+
+            std::stringstream stream;
+            stream    << std::setfill('0')
+                      << std::put_time(now_tm, "%FT%H:%M:")
+                      << std::setw(2) << (timestamp / 1000) % 60 << '.'
+                      << std::setw(3) << timestamp % 1000;
+
+            prefix = std::regex_replace(prefix, std::regex("ISO8601"), stream.str());
 
             char indexString[8];
             snprintf(indexString, 8, "%03d", maxIndex);