tungwaiyip.info

home

about me

links

Blog

< September 2016 >
SuMoTuWeThFrSa
     1 2 3
4 5 6 7 8 910
11121314151617
18192021222324
252627282930 

past articles »

Click for San Francisco, California Forecast

San Francisco, USA

 

Let's meet at 1am

My work needs me to setup computer system to work across the globe. A key issue is to have a common time reference. This gets tricky because of time zone. Just saying 12pm is imprecise. Which time zone is 12pm reference to? Is it 12pm in San Francisco? Or 12pm in London? Another complication is day light saving adjustment, which make time measure more irregular.

The standard practice is to use Coordinated Universal Time (UTC), i.e. Greenwich Mean Time. So everyone across the globe has a reference to the same standard time. Having a standard reference is great for computer system. But for us software engineers it is another quantity to juggle with. I often have to track time across systems. If the system responses something like 14:22, it is still hard to make sense of. Is it this afternoon? This morning? Or sometime in the future? Translating between local time and UTC is often necessity for me. But it is much harder to do mentally compares to, say translating between metrics and imperial unit.

One tip is I added a clock of Reykjavik, Iceland time on my cellphone. Iceland time happens to match UTC and Icelanders do not mess with daylight saving time. This gives me a easy read of current UTC time (8pm now, which is 1pm San Francisco time.)

I have a colleague who argues strongly that the entire world should adopt UTC time in actual daily use and do away with time zone. Standardization is probably very important for him. How practical is this for regular people? To this I said, let's have a meeting at 1am, UTC time (it is 6pm for your reference).

2016.09.08 comments

 

 

blog comments powered by Disqus

past articles »

 

BBC News

 

Coronavirus: Wuhan to shut public transport over outbreak (22 Jan 2020)

 

Jeff Bezos hack: UN experts demand probe of Saudi crown prince (22 Jan 2020)

 

Harvey Weinstein trial: Defence hits back after graphic prosecution claims (22 Jan 2020)

 

Trump says he plans to expand US travel ban (22 Jan 2020)

 

Jean-Paul Gaultier: Stars turn out for designer's final show (22 Jan 2020)

 

Macron berates Israeli police at Jerusalem church (22 Jan 2020)

 

Zimbabwe doctors end strike after billionaire's offer (22 Jan 2020)

 

Storm Gloria: Sea foam engulfs streets of Spanish town (22 Jan 2020)

 

Pierre Nkurunziza: Burundi leader to get ,000 and luxury villa (22 Jan 2020)

 

Terry Jones: Monty Python stars pay tribute to comedy great (22 Jan 2020)

more »

 

SF Gate

 

Ship traffic, Jan. 23 (22 Jan 2020)

 

Ship traffic, January 22 (21 Jan 2020)

 

Papyrus to close all California stores (21 Jan 2020)

 

Climate not considered a top 10 risk by CEOs, survey finds (20 Jan 2020)

 

The secretive company that might end privacy as we know it (20 Jan 2020)

 

Ship traffic, January 21 (20 Jan 2020)

more »


Site feed Updated: 2020-Jan-22 15:00