diff --git a/src/lang/english_US.txt b/src/lang/english_US.txt
--- a/src/lang/english_US.txt
+++ b/src/lang/english_US.txt
@@ -5516,10 +5516,10 @@ STR_VEHICLE_NAME_AIRCRAFT_POWERNAUT_HELI
 
 ##id 0x8800
 # Formatting of some strings
-STR_FORMAT_DATE_TINY                                            :{1:STRING}/{0:STRING}/{2:NUM}
+STR_FORMAT_DATE_TINY                                            :{1:ZEROFILL_NUM}/{0:ZEROFILL_NUM}/{2:NUM}
 STR_FORMAT_DATE_SHORT                                           :{STRING} {NUM}
 STR_FORMAT_DATE_LONG                                            :{1:STRING} {0:STRING}, {2:NUM}
-STR_FORMAT_DATE_ISO                                             :{2:NUM}-{1:STRING}-{0: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}