Bug#238786: Not a libc bug
reassign 238786 cyrus-imapd-2.4
retitle 238786 cyrus21-imapd: APPEND fails with Invalid date-time, on 64-bit architectures.
Previous 'gmtime returns NULL for time_ts larger than 40 bits on Alpha' title
was wrong. First it returns NULL only for larger than about 2**58. Second
it is not bug, returning NULL is not a bug, it is just error condition
conforming to POSIX standards. See my posts to bug #200641.
Thus reasigning back to cyrus-imapd