04.08: find a portable way to obtain the timezone offset

Portable GMT offset calculation to display correct
time on GSM.

Change-Id: I673f17af2550c9708c4771e4ea4eafbbfafbb824
This commit is contained in:
Benoit Bolsee 2017-07-05 12:57:16 +02:00 committed by Neels Hofmeyr
parent e2e41c1e61
commit 38bb344a47
1 changed files with 10 additions and 3 deletions

View File

@ -496,12 +496,19 @@ int gsm48_tx_mm_info(struct gsm_subscriber_connection *conn)
else {
/* Need to get GSM offset and convert into 15 min units */
/* This probably breaks if gmtoff returns a value not evenly divisible by 15? */
local_time = localtime(&cur_t);
#ifdef HAVE_TM_GMTOFF_IN_TM
local_time = localtime(&cur_t);
tzunits = (local_time->tm_gmtoff/60)/15;
#else
#warning find a portable way to obtain the timezone offset
tzunits = 0;
/* find timezone offset */
time_t utc;
double offsetFromUTC;
utc = mktime(gmt_time);
local_time = localtime(&cur_t);
offsetFromUTC = difftime(cur_t, utc);
if (local_time->tm_isdst)
offsetFromUTC += 3600.0;
tzunits = ((int)offsetFromUTC) / 60 / 15;
#endif
if (tzunits < 0) {
tzunits = tzunits/-1;