util: Use std::chrono for time getters

src/util/time.cpp

@@ -90,6 +90,14 @@ template std::chrono::seconds GetTime();
 template std::chrono::milliseconds GetTime();
 template std::chrono::microseconds GetTime();
 
+template <typename T>
+static T GetSystemTime()
+{
+    const auto now = std::chrono::duration_cast<T>(std::chrono::system_clock::now().time_since_epoch());
+    assert(now.count() > 0);
+    return now;
+}
+
 void SetMockTime(int64_t nMockTimeIn)
 {
     Assert(nMockTimeIn >= 0);
@@ -103,23 +111,17 @@ int64_t GetMockTime()
 
 int64_t GetTimeMillis()
 {
-    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
-                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_milliseconds();
-    assert(now > 0);
-    return now;
+    return int64_t{GetSystemTime<std::chrono::milliseconds>().count()};
 }
 
 int64_t GetTimeMicros()
 {
-    int64_t now = (boost::posix_time::microsec_clock::universal_time() -
-                   boost::posix_time::ptime(boost::gregorian::date(1970,1,1))).total_microseconds();
-    assert(now > 0);
-    return now;
+    return int64_t{GetSystemTime<std::chrono::microseconds>().count()};
 }
 
 int64_t GetSystemTimeInSeconds()
 {
-    return GetTimeMicros()/1000000;
+    return int64_t{GetSystemTime<std::chrono::seconds>().count()};
 }
 
 std::string FormatISO8601DateTime(int64_t nTime) {