Fix error.

src/common/datatypes/Date.cpp

@@ -206,10 +206,11 @@ void Time::subDuration(const Duration& duration) {
 }
 
 std::string Time::toString() const {
-  auto microsecStr = folly::stringPrintf("%.9f", static_cast<uint32_t>(microsec) / 1000000.0);
-  auto decimalPart = decimal(microsecStr);
-  // It's in current timezone already
-  return folly::stringPrintf("%02d:%02d:%02d%s", hour, minute, sec, decimalPart.c_str());
+  return folly::sformat("{:0>2}:{:0>2}:{:0>2}.{:0>6}000",
+                        static_cast<uint8_t>(hour),
+                        static_cast<uint8_t>(minute),
+                        static_cast<uint8_t>(sec),
+                        static_cast<uint32_t>(microsec));
 }
 
 void DateTime::addDuration(const Duration& duration) {