[tz] [PROPOSED 1/6] Add comment re UT offsets equal to -2**31

[Paul Eggert via tz]

---
 localtime.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/localtime.c b/localtime.c
index a506f097..917e957d 100644
--- a/localtime.c
+++ b/localtime.c
@@ -507,7 +507,8 @@ typedef int_fast64_t int_fast32_2s;
 #endif
 
 struct ttinfo {                                /* time type information */
-       int_least32_t   tt_utoff;       /* UT offset in seconds */
+       int_least32_t   tt_utoff;       /* UT offset in seconds; in the range
+                                          -2**31 + 1 .. 2**31 - 1  */
        desigidx_type   tt_desigidx;    /* abbreviation list index */
        bool            tt_isdst;       /* used to set tm_isdst */
        bool            tt_ttisstd;     /* transition is std time */
-- 
2.52.0