dst

I'm working on a Rails app where I need to find the Daylight Saving Time start and end dates given a specific offset or timezone. I basically save in my database the timezone offset received from a user's browser( "+3" , "-5" ) and I want to modify it when it changes because of daylight saving time. I know Time instance variables have the dst? and isdst methods which return true or false if the date stored in them is in the daylight saving time or not. > Time.new.isdst => true But using this to find the Daylight Saving Time beginning and end dates would take too many resources and I also have

Is there a way in Oracle to select the date on which daylight savings will switch over for my locale? Something vaguely equivalent to this would be nice: SELECT CHANGEOVER_DATE FROM SOME_SYSTEM_TABLE WHERE DATE_TYPE = 'DAYLIGHT_SAVINGS_CHANGEOVER' AND TO_CHAR(CHANGEOVER_DATE,'YYYY') = TO_CHAR(SYSDATE,'YYYY'); -- in the current year Edit: I was hoping for a solution that would not require changes when Congress adjusts DST laws, as they did in 2007. The posted solutions will work, though. We use the following two functions to calculate the start and end dates for any given year (post 2007, US).

I'm using QuickBooks Web Connector to pull employee records out of QuickBooks Desktop on a Windows 8.1 machine using QBXML requests. Is there a reason the TimeModified time stamps are returning an offset that does not account for Daylight Savings time? Is there a way to get the current time on the host system? It is currently returning "2014-03-27T14:20:53-05:00" for TimeModified, even though the current timezone is set to Eastern Time with "Adjust for Daylight Savings Time" enabled. The offset should be -04:00. The QBXML request: <?xml version="1.0" encoding="utf-8"?> <?qbxml version="12.0"?>

In the time.h header for the daylight global variable it says: "This variable has a nonzero value if Daylight Saving Time rules apply. A nonzero value does not necessarily mean that Daylight Saving Time is now in effect; it means only that Daylight Saving Time is sometimes in effect." Now I've noticed that in both Solaris 11.2 and Linux the "daylight" variable is being set to 1, even though my time-zone does not use daylight savings at all (Australia/Brisbane). Sample code confirms this, if I run tzset and output the global variables we get: daylight = 1 tz[0] = [AEST] tz[1] = [AEDT] timezone

The Central European Daylight Saving Time begins on last Sunday in March. We set our clocks from 02:00 to 03:00. What happens if I do timestamp calcuations in a database request - lets say at 01:59? UPDATE sessions SET aliveuntil = (CURRENT_TIMESTAMP + INTERVAL '1' MINUTE) WHERE id = ? Do I get 03:00 as result or 02:00? And what about the over way around if we set our clocks from 03:00 to 02:00? SELECT id FROM sessions WHERE aliveuntil < (CURRENT_TIMESTAMP - INTERVAL '1' MINUTE) After time changed from 03:00 to 02:00... what happens with the (CURRENT_TIMESTAMP - INTERVAL '1' MINUTE) at 02:00?

i'm a little lost in the timezone :) I have data stored with the time in UTC. The server is in the Netherlands, so we live in utc+1 (now, with daylightsavingtime, in utc + 2) Now a client says: give me the data from august 5th. So i have to calculate the utc time from 'his time'. For that i have to know: what is your utc offset (we stored that in his profile, let's say utc -6) are you in daylightsavingtime (because then we have to add +1 and make the utc offset -5) Then my questions: Can i ask the .Net framework: does country XX have daylightsavingtime? Can i ask the .Net framework: is 08-05

I want to detect if I'm in winter or summer time. My current approach is: if date +%Z | grep -e CET -e EST; then # I'm in winter time else # I'm in summer time fi which have obvious drawback as you have to know all the timezone names. Perl to the rescue: if perl -e 'exit ((localtime)[8])' ; then echo winter else echo summer fi I don't now if this exactly answers your question, but it gives you some tools to help you better understand and test whats going on. You can use date and environment-var TZ to help you. So for example I live in Sweden so my timezone location is Europe/Stockholm . So in

Issuing the following SQL generates different results thru PL/SQL, ODBC and JDBC: select sysdate from dual When running it on PL/SQL or ODBC, the date and time is correct. On JDBC it comes with an hour less. It seems that it is not considering daylight savings. For example, on PL/SQL the result is 2012-11-05 16:53:53.0 and on JDBC it is 2012-11-05 15:53:53.0 . It happens only on some databases. Changing the database timezone ( select dbtimezone from dual ) doesn't seems to affect the results. The command is executing on Brazil. Raw GMT offset is -03:00, current offset is -02:00 because of

I know there a lot of questions and answers of this already, but unfortunately I think my situation may be unique? For some reason, the time-change seems to be making the day calculate as one day less than it should be calculating. Here is my PHP that I was using and it was working great, until it started to overlap a start and end date that was BEFORE daylight savings, and AFTER daylight savings, respectively (FYI, this is a recent issue, since daylight savings time starts this weekend!): //$lastDate and $firstDate are 2 unix timestamps with valid month, day, and year values. //The times are