Fixing Issue-915

[phidebian]

commit 1a9d8ad introduced a bug
printf "%(%Y-%m-%d)T\n" "now in 10 week"
produce
2025-11-13
This fix produce the expecteed
2026-01-22

src/lib/libast/tm/tmxdate.c::1456
case TM_PARTS+4:
tm = tmxtm(tm, tmxtime(tm, zone), tm->tm_zone, 0);
tm->tm_hour += m * 7 * 24;
set |= DAY; <======= TYPO HERE
goto clear_hour;

Since we are updating tm_hour then set HOUR

[McDutchie]

It still seems very buggy.

Today is 2026-01-22.

$ printf "%(%Y-%m-%d)T\n" "10 weeks"
2026-04-02
printf "%(%Y-%m-%d)T\n" "now in 10 weeks"
2026-04-02

So far, so good. But:

$ printf "%(%Y-%m-%d)T\n" "2026-01-21 in 10 weeks"                                                
2026-04-02
$ printf "%(%Y-%m-%d)T\n" "2026-01-20 in 10 weeks"
2026-04-02
$ printf "%(%Y-%m-%d)T\n" "2026-01-01 in 10 weeks"
2026-04-02
$ printf "%(%Y-%m-%d)T\n" "2025-31-01 in 10 weeks"
2025-04-11
$ printf "%(%Y-%m-%d)T\n" "2025-01-01 in 10 weeks"
2025-04-02

None of that makes any sense, does it?

[phidebian]

@McDutchie Yes it was very very buggy and now it is very buggy, I doubt anyone use that.

Yet it is still possible to do the math the right way $((...)) arith instead of the cobol like "now in 10 weeks".

The following shows how to get 'now" then add up whatever formula you need.
(Any online IA will produce that formula ;-) )

TC$ printf -v now '%(%s)T' now ; echo $now
1769147179

TC$ then=$((now+(10*7*24*60*60))) ; echo $then
1775195179

TC$ printf "%(%Y-%m-%d %H:%M:%S %s.%N)T\n" $now.000000000 
2026-01-23 05:46:19 1769147179.000000000

TC$ printf "%(%Y-%m-%d %H:%M:%S %s.%N)T\n" $then.000000000
2026-04-03 05:46:19 1775195179.000000000

TC$ date +"%Y-%m-%d %H:%M:%S %s.%N" --date=@$then                           
2026-04-03 07:46:19 1775195179.000000000

Use this as a workaround until someone fix this bug...

[phidebian]

@McDutchie Welcome back by the way :-)

[McDutchie]

Thanks. :)

I can't easily think of a regression test since the result changes by the day, so I'll just merge this now.