zOs/SQL/EXTSTDIF

with t (t) as                                                           00001000
(                                                                       00002000
  select current timestamp from sysibm.sysDummy1                        00003000
  union all select '2014-06-17-00.00.00' from sysibm.sysDummy1          00004000
)                                                                       00005000
, u (a, b) as                                                           00006000
(                                                                       00007000
  select t, t - 1 minute from t                                         00010000
  union all select t, t + 2 hour from t                                 00020000
  union all select t, t - 3 day  from t                                 00030000
  union all select t, t + 4 month  from t                               00040006
)                                                                       00050000
select a - b minus                                                      00060006
    , timestampDiff(2, char(a-b)) "secs"                                00061007
    , timestampDiff(16, char(a-b)) "days"                               00062007
    , timestampDiff(256, char(a-b)) "years"                             00062107
    , a, b                                                              00063006
    from u                                                              00070000