1998/1/4: 1498 = 14:98 = integer ratio of 1 to 7
1998/1/4: 9814 = 98:14 = integer ratio of 7 to 1
1998/1/8: 010898 = 010:898 = each is palindrome
1998/1/11: 01111998 = 0111:1998 = integer ratio of 1 to 18
1998/1/11: 011198 = 011:198 = integer ratio of 1 to 18
1998/1/11: 19980111 = 1998:0111 = integer ratio of 18 to 1
1998/2/8: 020898 = 020:898 = each is palindrome
1998/2/14: 021498 = 02:14:98 = geometric series of ratio 7
1998/2/17: 021798 = 021:798 = integer ratio of 1 to 38
1998/2/21: 022198 = 022:198 = integer ratio of 1 to 9
1998/2/22: 02221998 = 0222:1998 = integer ratio of 1 to 9
1998/2/22: 19980222 = 1998:0222 = integer ratio of 9 to 1
1998/3/8: 030898 = 030:898 = each is palindrome
1998/3/31: 033198 = 033:198 = integer ratio of 1 to 6
1998/4/1: 1498 = 14:98 = integer ratio of 1 to 7
1998/4/8: 040898 = 040:898 = each is palindrome
1998/4/9: 4998 = 49:98 = integer ratio of 1 to 2
1998/4/9: 9849 = 98:49 = integer ratio of 2 to 1
1998/4/27: 042798 = 042:798 = integer ratio of 1 to 19
1998/5/8: 050898 = 050:898 = each is palindrome
1998/6/8: 060898 = 060:898 = each is palindrome
1998/7/6: 9876 = 9:8:7:6 = arthimetic series of increment -1
1998/7/8: 070898 = 070:898 = each is palindrome
1998/8/1: 010898 = 010:898 = each is palindrome
1998/8/2: 020898 = 020:898 = each is palindrome
1998/8/3: 030898 = 030:898 = each is palindrome
1998/8/4: 040898 = 040:898 = each is palindrome
1998/8/5: 050898 = 050:898 = each is palindrome
1998/8/6: 060898 = 060:898 = each is palindrome
1998/8/7: 070898 = 070:898 = each is palindrome
1998/8/8: 080898 = 080:898 = each is palindrome
1998/8/9: 090898 = 090:898 = each is palindrome
1998/8/9: 8998 = palindrome
1998/8/9: 98089 = palindrome
1998/8/9: 9889 = palindrome
1998/8/9: 9898 = cyclic permutation symmetric
1998/8/28: 082898 = 08:28:98 = geometric series of ratio 3.5
1998/9/4: 4998 = 49:98 = integer ratio of 1 to 2
1998/9/8: 090898 = 090:898 = each is palindrome
1998/9/8: 8998 = palindrome
1998/9/8: 9898 = cyclic permutation symmetric
1998/10/1: 981001 = 981:001 = integer ratio of 981 to 1
1998/10/3: 981003 = 981:003 = integer ratio of 327 to 1
1998/10/9: 981009 = 981:009 = integer ratio of 109 to 1
1998/10/18: 101898 = 101:898 = each is palindrome
1998/11/1: 01111998 = 0111:1998 = integer ratio of 1 to 18
1998/11/1: 011198 = 011:198 = integer ratio of 1 to 18
1998/11/9: 981109 = 981:109 = integer ratio of 9 to 1
1998/11/18: 111898 = 111:898 = each is palindrome
1998/12/18: 121898 = 121:898 = each is palindrome