I want to select a date and as I select it, it should show me the data for that particular date.
Why do you not want to use a date field in order to select that date? Using a field is by a very large margin much simpler than selecting a date without using a field. So I wouldn't try that without a very good reason for doing so as your alternative would require a lot of buttons, scripts and global variables just to select that date. (I've done that to create a calendar format date picker to use in FileMaker Go in place of the "spinning wheels" date selector that FM GO otherwise uses for entering dates.)
I'm using a portal for displaying record for a specific date for that artist. I've uploaded an image of my layout. I've created an extra field to store the selected date in the artist table. Then I'm using that field to filter data in the portal. Whenever the user changes the date I'm committing it and portal has been set to filter data for that date.
My point is why can't I just place a date control on the layout and make the portal look at it for the filtering job. Why always commit a date to filter record each time I want to browse for a different date.
And my point is that you can use a field for precisely that purpose. Put a date field, very likely a global date field on your layout and set it up as a match field in the relationship. The date you select or enter into that date field will control what records appear in the portal.
Yes, records will have to be committed, but this can be done via a script trigger on that date field so that the user need only select or enter a date.
If we were to use a variable for the date, you would not be able to use the date as a match field and you'd trouble using it in a portal filter as you'd have to use Refresh Window [Cached Join Results] which can really slow the update of your layout down if there are a lot of records in your filtered portal.