I wish to set my clock 5 minutes quicker than the true time. A technique to do that is to disable auto-set time and set the time manually.
However this fashion the time is flawed doing date +%s will give incorrect timestamps. Moreover, some web sites and apps don’t work correctly because of this, resembling TOTP.
So I attempted setting a customized timezone offset with zic from https://github.com/eggert/tz.
$ echo "Zone Asia/Kolkata+05 5:35 - IST+05" | zic -b fats -d . -
This gave me a legitimate TZinf file.
$ file Asia/Kolkata+05
Asia/Kolkata+05: timezone information (fats), model 2, no gmt time flags, no std time flags, no leap seconds, no transition instances, 1 native time kind, 7 abbreviation chars
I attempted setting the timezone with systemsetup however it would not permit this timezone. Chatgpt suggests disabling SIP and shifting the file, however I am unable to do this as a result of I am on a piece laptop computer.
$ sudo systemsetup -settimezone ~/Asia/Kolkata+05
/Customers/karan/Asia/Kolkata+05 isn't a legitimate timezone. The command 'listtimezones' will present a listing of legitimate time zones.
$ sudo cp Asia/Kolkata+05 /usr/share/zoneinfo/Asia/
cp: /usr/share/zoneinfo/Asia/Kolkata+05: Operation not permitted
Exporting the TZ variable to this timezone works with the date and gdate utilities, however I wish to see the system time with this offset.
$ export TZ="/Customers/karan/Asia/Kolkata+05"
$ date
Wed Dec 25 03:42:09 IST+05 2024
$ gdate
Wed Dec 25 03:42:15 IST+05 2024
I additionally tried setting a symlink to native time, however it resets the timezone to Pacific time.
sudo ln -sf ~/Asia/Kolkata+05 /and many others/localtime
