To reproduce:
1. Verify that TZ environment variable is not defined
2. Verify that $KOHA_CONF does not contain <timezone>
3. Run `date` to verify that you have a local time different than UTC
4. prove t/DateUtils.t

Expected output:
% prove t/DateUtils.t
t/DateUtils.t .. 1/76
#   Failed test 'dt_from_string handles seconds with 1 decimal place'
#   at t/DateUtils.t line 130.
#          got: '1325447940'
#     expected: '1325462340'

#   Failed test 'dt_from_string handles seconds with 2 decimal places'
#   at t/DateUtils.t line 133.
#          got: '1325447940'
#     expected: '1325462340'

#   Failed test 'dt_from_string handles seconds with 3 decimal places'
#   at t/DateUtils.t line 136.
#          got: '1325447999'
#     expected: '1325462399'

#   Failed test 'dt_from_string handles seconds with 3 decimal places and a timezone'
#   at t/DateUtils.t line 139.
#          got: '1325447999'
#     expected: '1325462399'
# Looks like you failed 4 tests of 76.