diff --git a/src/lang/english.txt b/src/lang/english.txt
index 352119a66a..c5267325c9 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -5521,10 +5521,10 @@ STR_VEHICLE_NAME_AIRCRAFT_POWERNAUT_HELICOPTER                  :Powernaut Helic
 
 ##id 0x8800
 # Formatting of some strings
-STR_FORMAT_DATE_TINY                                            :{RAW_STRING}-{RAW_STRING}-{NUM}
+STR_FORMAT_DATE_TINY                                            :{ZEROFILL_NUM}-{ZEROFILL_NUM}-{NUM}
 STR_FORMAT_DATE_SHORT                                           :{STRING} {NUM}
 STR_FORMAT_DATE_LONG                                            :{STRING} {STRING} {NUM}
-STR_FORMAT_DATE_ISO                                             :{2:NUM}-{1:RAW_STRING}-{0:RAW_STRING}
+STR_FORMAT_DATE_ISO                                             :{2:NUM}-{1:ZEROFILL_NUM}-{0:ZEROFILL_NUM}
 
 STR_FORMAT_COMPANY_NUM                                          :(Company {COMMA})
 STR_FORMAT_GROUP_NAME                                           :Group {COMMA}
diff --git a/src/strings.cpp b/src/strings.cpp
index a143d83dee..4fe0304561 100644
--- a/src/strings.cpp
+++ b/src/strings.cpp
@@ -448,13 +448,8 @@ static char *FormatTinyOrISODate(char *buff, Date date, StringID str, const char
 	YearMonthDay ymd;
 	ConvertDateToYMD(date, &ymd);
 
-	char day[3];
-	char month[3];
-	/* We want to zero-pad the days and months */
-	seprintf(day,   lastof(day),   "%02i", ymd.day);
-	seprintf(month, lastof(month), "%02i", ymd.month + 1);
-
-	int64 args[] = {(int64)(size_t)day, (int64)(size_t)month, ymd.year};
+	/* Day and month are zero-padded with ZEROFILL_NUM, hence the two 2s. */
+	int64 args[] = {ymd.day, 2, ymd.month + 1, 2, ymd.year};
 	StringParameters tmp_params(args);
 	return FormatString(buff, GetStringPtr(str), &tmp_params, last);
 }