Add requirements marks. No code changes.

FossilOrigin-Name: 5e0d43ab55de006b20c58cb18b938d1c7b658e51

src/date.c

@@ -426,6 +426,10 @@ static void clearYMD_HMS_TZ(DateTime *p){
 **
 ** If the sqlite3GlobalConfig.bLocaltimeFault variable is true then this
 ** routine will always fail.
+**
+** EVIDENCE-OF: R-62172-00036 In this implementation, the standard C
+** library function localtime_r() is used to assist in the calculation of
+** local time.
 */
 static int osLocaltime(time_t *t, struct tm *pTm){
   int rc;
@@ -482,6 +486,11 @@ static sqlite3_int64 localtimeOffset(
   x = *p;
   computeYMD_HMS(&x);
   if( x.Y<1971 || x.Y>=2038 ){
+    /* EVIDENCE-OF: R-55269-29598 The localtime_r() C function normally only
+    ** works for years between 1970 and 2037. For dates outside this range,
+    ** SQLite attempts to map the year into an equivalent year within this
+    ** range, do the calculation, then map the year back.
+    */
     x.Y = 2000;
     x.M = 1;
     x.D = 1;