Building a "This Week" & "Next Week" Link Quiery

Building a "This Week" & "Next Week" Link Quiery

I'm building a script for an events website and I have shortcut links for
"Today, 7 Days, 14 Days, 30 Days & 60 Days, using PHP to get each day
count from today which works fine but I'd prefer to have it as "Today,
This Week, Next Week" and then let the users do a custom search for
anything further in the future. Problem is I have no idea how to get the
weeks for this type of calculation. For example I could do this week as
"From today to +7" and then do next week as "Today +7 to Today +14" but
this would be a bit confusing, so what I want to do is:
Today = Today //I have the script for this
This Week = Today (Whichever day we are on) to Sunday
Next Week = Next Monday to Next Sunday
Any Ideas how this is done?