t0006: add more tests with a negative TZ offset

This test doesn't systematically check a negative timezone offset. Add a
test for each format that outputs the offset to improve our test
coverage.

Signed-off-by: Beat Bolli <[email protected]>

Author: bbolli

t/t0006-date.sh

@@ -69,6 +69,14 @@ check_show 'format:%s' '123456789 +1234' 123456789
 check_show 'format:%s' '123456789 -1234' 123456789
 check_show 'format-local:%s' '123456789 -1234' 123456789
 
+# negative TZ offset
+TIME='1466000000 -0200'
+check_show iso8601 "$TIME" '2016-06-15 12:13:20 -0200'
+check_show iso8601-strict "$TIME" '2016-06-15T12:13:20-02:00'
+check_show rfc2822 "$TIME" 'Wed, 15 Jun 2016 12:13:20 -0200'
+check_show default "$TIME" 'Wed Jun 15 12:13:20 2016 -0200'
+check_show raw "$TIME" '1466000000 -0200'
+
 # arbitrary time absurdly far in the future
 FUTURE="5758122296 -0400"
 check_show iso       "$FUTURE" "2152-06-19 18:24:56 -0400" TIME_IS_64BIT,TIME_T_IS_64BIT