UTC time zone chart need to calc difference depending..

[RodM]

TIME ZONE

 

UTC  -10

UTC  -9

UTC  -8  Pacific

UTC  -7 Mountain

UTC- 6 Central

UTC -5 Eastern

UTC  -4

UTC  0  greenwhich mean time

UTC +1

UTC  +2  European standard

 

 

 

Generally difference is 3 hours..  + ahead or   - behind  hours depends on where my system is located either on the WEST or the EAST coast... and where the client is ..

 

 

My clients  systems can be anywhere on the UTC chart...   and their clients can ahead or behind

 

 

I need to get a   + or -  number of hours returned  from where I am located

 using 2 variables and 2 list similar to the chart above

 

 

Does that make since...

 

 

 

[bcooney]

this may help:

 

http://www.briandunning.com/cf/1442

[RodM]

I currently can figure it in my head better than..

thanks   I found that link already..      I don't have the UTC time afar... from my current timestamp.

 

 

I am using typical UTC chart is similar as I briefed out above...  picking 2 UTC locations using a List

 

 

I just need to get the difference...

in plus or minus hours   ...from whatever the reference point is...

 

 

as PST time is UTC -8       and East coast  is -5   diff =   - 3 behind    I probably not making sense

 

but what if my operation is based out of UK...   I set my UTC time in my system..  then my new client is in Philippines.. I set my client from UTC + 10 maybe      then what be my difference.. + or - ?

[comment]

This is 4th grade math: subtract your offset from their offset; add the result to your time to get their time.

[RodM]

not really...   maybe your not clear..

 

if the system is located in utc-8 

  and client is utc -5   eastern time...   that answer +3 hrs ahead of my system time       is the return i need, a number + - from the system to the  the client

 

I am not dealing with TIME in ..  I don't know their time, we just use a simple UTC list  

          and sometimes the client or System might be in the next day or behind a day maybe... 

 

What if system is in UTC -5 location...   the client is west coast in UTC -8   the answer is -3 hrs behind..

 

Same number but behind reference#

 

 

Then from Greenwich which is 0         we go the other way on the chart...  into UTC + numbers

 

 

 

That makes it even more complicated...   to me Mr wise person..   Please oh pls, give me a couple minutes, help me on my 4th grade math...

 

 

 

Return me... + or - from my reference UTC location my call center is located from the client location?...

 

I have a call center ..  

They could be anywhere in the UTC..   as the call center we think  ahead or behind my time... set message time stamp to their time

 

Set set the UTC of the call center..  when we add clients we set the UTC of their location...  simple... not ask them da.. what time are you now?  today or tomorrow?

 

 

 

 

 

 

 

a

[comment]

subtract your offset from their offset; ...

 

If you have two fields, SystemOffset and ClientOffset, then the difference (from the point-of-view of the system) is =

 

ClientOffset - SystemOffset

Example 1:

System is located in Oregon (currently UTC-7), client is in New York (currently UTC-4).

SystemOffset = -7

ClientOffset = -4

difference = -4 - (-7) = 3

The difference is a positive number, meaning that the client is 3 hours ahead of the system.

Example 2:

System is located in New York (currently UTC-4) , client is in Oregon (currently UTC-7).

SystemOffset = -4

ClientOffset = -7

difference = -7 - (-4) = -3

Here the difference is a negative number, meaning that the client is 3 hours behind the system.

 

 

 

 

... add the result to your time to get their time.

 

The following calculation =

Let (
diff = ClientOffset - SystemOffset
;
Get ( CurrentTimeStamp ) + Time ( diff ; 0 ; 0 )
)

will return the client's timestamp at the time the calculation is performed at system's location..

 

In the first example, if you perform the calculation in Oregon on September 10, 2013 at 8:00 am, it will return September 10, 2013 11:00 am as the corresponding time in New York.

http://www.timeanddate.com/worldclock/converted.html?iso=20130910T08&p1=202&p2=179

 

In the second example, if you perform the calculation in New York on September 10, 2013 at 8:00 am, it will return September 10, 2013 5:00 am as the corresponding time in Oregon.

http://www.timeanddate.com/worldclock/converted.html?iso=20130910T08&p1=179&p2=202

 

This is the easy part. The difficult part is knowing what is the client's current offset, because it changes when daylight saving starts and ends.

[RodM]

I had the simple subtract or number of hours differnt

I had problems figuring ahead time or behind.. 

Seem like you have done this b4..
Thanks so much..

[bcooney]

"The difficult part is knowing what is the client's current offset, because it changes when daylight saving starts and ends."

 

If I can count on their system date/time (most are synced to a server), then why is this difficult?

[comment]

I believe "client" here means the person on the other side of a phone call, not a node on the computer network. If the offset is stored in a field of the Clients table, and the client is in a time zone that uses DST, then the stored data is wrong during some parts of the year.

[bcooney]

Understood.