# Timezones and daylight saving

Do we really need them and do we really need ones which change?

Logically thinking, if there was a world time which didn't change,
then appointments, schedules and whatever else should always be
possible to synchronize internationally without any ambiguity.

The military uses UTC (GMT or Zulu) time which remains constant,
radio amateurs also use this singular zone when logging or arranging
schedules.


## Why am I even talking about this?

My server is located in Amsterdam and the VM is defaulted to CET, my
local machine is GMT. Both of these change dependant on time of year.
GMT switches to BST (UTC +1hr) at 01:00 on the last Sunday of March
until 02:00 the last Sunday of October were it returns to GMT. I'm
fairly sure CET follows the same schedule but is GMT +1 to begin...

I send my email from the server so it has the server time. I also
sync files between the server and my local machine so it's obviously
much better if their clocks are in sync.

This led me to the following questions: 
* Why do they change? 
* Do they need to change?
* What are the advantages and disadvantages?
* Is there a better way?


## Would it be weird your morning starting at 13:00?

I guess we have gotten used to the small hours being the very early
morning and the larger hours being the evening. But would it really
make any difference? Would the benefits of a common global time
outweigh the perceived problems? How much computation is performed
just converting dates from one zone to another?


## What really matters?

I think what really matters are daylight hours. There have been
various studies[0] performed by the British government over time and
statistical analysis by safety bodies like RoSPA that strongly
suggest that with extended daylight hours there are less road traffic
deaths. Another benefit is that less electricity would be consumed
keeping the lights on during darkness. 

One campaign, Lighter Later, suggested a change to increased daylight
hours, GMT+1 in winter and GMT+2 in summer, could "save almost
500,000 tonnes of CO2 each year, equivalent to taking 185,000 cars
off the road permanently". That's quite a claim.

Why can't we just change the alarm clock and not the time? 

[0](gopher://gopherpedia.com/0/British%20Summer%20Time)