diff --git a/include/coreinit/time.h b/include/coreinit/time.h
index aed728d..8e6eea4 100644
--- a/include/coreinit/time.h
+++ b/include/coreinit/time.h
@@ -16,6 +16,7 @@ typedef struct OSCalendarTime OSCalendarTime;
 typedef int32_t OSTick;
 typedef int64_t OSTime;
 
+//! Same as std c struct tm but with msec and usec added.
 struct OSCalendarTime
 {
    int32_t tm_sec;
@@ -24,6 +25,10 @@ struct OSCalendarTime
    int32_t tm_mday;
    int32_t tm_mon;
    int32_t tm_year;
+   int32_t tm_wday;
+   int32_t tm_yday;
+   int32_t tm_msec;
+   int32_t tm_usec;
 };
 CHECK_OFFSET(OSCalendarTime, 0x00, tm_sec);
 CHECK_OFFSET(OSCalendarTime, 0x04, tm_min);
@@ -31,7 +36,11 @@ CHECK_OFFSET(OSCalendarTime, 0x08, tm_hour);
 CHECK_OFFSET(OSCalendarTime, 0x0C, tm_mday);
 CHECK_OFFSET(OSCalendarTime, 0x10, tm_mon);
 CHECK_OFFSET(OSCalendarTime, 0x14, tm_year);
-CHECK_SIZE(OSCalendarTime, 0x18);
+CHECK_OFFSET(OSCalendarTime, 0x18, tm_wday);
+CHECK_OFFSET(OSCalendarTime, 0x1C, tm_yday);
+CHECK_OFFSET(OSCalendarTime, 0x20, tm_msec);
+CHECK_OFFSET(OSCalendarTime, 0x24, tm_usec);
+CHECK_SIZE(OSCalendarTime, 0x28);
 
 #define OSOneSecond ((OSGetSystemInfo()->clockSpeed) / 4)
 #define OSMilliseconds(val) ((((uint64_t)(val)) * (uint64_t)(OSOneSecond)) / 1000ull)