These days I'm often travelling long distances; whether it's to Asia or Detroit with work; or San Francisco for the MeeGo and JavaOne Conferences.
Ten hour flights are rarely fun; but when combined with a ten hour time difference? The jet lag can destroy you.
However, I trust a clock when I see it. So if I can convince myself that the time isn't changing in one big jump, jet lag is less of an issue. I used to do this with my watch: every two hours on a ten hour flight with an eight hour time difference: move my watch forward two hours. By speeding up, or slowing down time, I find it excellent for transitioning gradually to my destination timezone.
My N9's standby screen provides an opportunity to do this automatically: every time I glance at my phone on the flight, it could show me the right "transient" time.
I prototyped it with a spreadsheet (download), for a recent trip to Korea, to see how effective it would be before writing an app:
To try it out, first off, enter the local departure and arrival times; and the timezone difference:
If travelling eastwards, the time difference will be positive. If travelling westwards, it will be negative.
A shell script will then be shown in column E. Copy this column and paste it into a text editor. Copy the resulting script to your UNIX-based mobile device (N9, N950, N900, N8x0, jailbroken iPad).
On a Harmattan device, the script needs to be run in develsh:
~ $ develsh outbound.sh
On everything else it needs to be run as root:
Jaffas-iPad:~ mobile$ su -
Jaffas-Ipad:~ root# sh outbound.sh
If run with screen or nohup, you shouldn't even need to keep the terminal open.
Obviously the next step is an app. Is it something you'd be interested in? Is there a nice Qt API for changing the time? Are there Qt APIs for looking up timezones, and setting the device's timezone?