Daylight savings and software patches

Pakistan has (quiet hastly) jumped on the daylight savings bandwagon. We've done this twice in the past and failed each time, although this time round the rationale is quiet understandable ie saving of energy.
I'm on ubuntu ...and havent received *ANY* alert for upgrading the daylight savings patch. I wonder if one is available for Windoz? I'm not worried for my system ...since I'll just change the timezone to Bangladesh as its +6 GMT to keep all the other timezones in synch. But what about banks, airlines and other such businesses where local time and timezones is critical?

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