Design advice for setting users default time

Question

I have an application that in a number of different places requires that records when being updated or created are shown to default to the user's current date. Depending on the location of the user, this could be a different day than where the server is.
All of the relevant fields in the database tables are using a datatype of "TIMESTAMP WITH TIMEZONE". When a users account is initially created, the timezone that the user is in is saved. When the user logs on, an "alter session set time_zone" command runs on the database to change the time zone of the current session.
When a user updates or creates a record and one of the field(s) requires to display the current date of the user, I call a ViewObject which runs a query to "select current_timestamp from dual" to return the current date from the database and populate the field with this.
I've realised that I'm creating a considerable overhead as this view object may be queried dozens of times during a users session and was thinking of running it once when the user logs on and storing the "USER_DATE" as a session variable - then I can simply refer to this each time, instead of many round-trips off to the database. Obviously there is a risk if the user logs on just before midnight and stays on until after that the date will be incorrect but this is extremely unlikely as the application is only used during normal business hours up to 9pm as an exception
Am I heading down the right track here or doing something daft (and missing something far more simple that I should be doing !)
Cheers,
Brent

Answer 1

Hi Frank,
Thanks for that - after 8 years of working with Oracle Forms and afterwards the same again with ADF, I still find it hard sometimes when using ADF to understand the best approach to a particular problem - there is so many different ways of doing things/where to put the code/how to call it etc... ! Things seemed so much simplier back in the Forms days !
Chandra - thanks for the information but this doesn't suit my requirements - I originally went down that path thinking/expecting it to be the holy grail but ran into all sorts of problems as it means that the dates are always being converted into users timezone regardless of whether or not they are creating the transaction or viewing an earlier one. I need the correct "date" to be stored in the database when a user creates/updates a record (for example in California) and this needs to be preserved for other users in different timezones. For example, when a management user in London views that record, the date has got to remain the date that the user entered, and not what the date was in London at the time (eg user entered 14th Feb (23:00) - when London user views it, it must still say 14th Feb even though it was the 15th in London at the time). Global settings like you are using in the adf-config file made this difficult. This is why I went back to stripping all timezone settings back out of the ADF application and relied on database session timezones instead - and when displaying a default date to the user, use the timestamp from the database to ensure the users "date" is displayed.
Cheers,
Brent