Rest day on Monday.
Today is a significant week.
When you get to Sunday you will have finished 6 weeks, or half of your 12-week training program for the half marathon. I am also going to ask you to run a 5-K race at the end of the week as a test of your ability. Since I'm asking you to run a 5-K race this weekend, you might want to opt for the rest. Make it easy on yourself. Don't feel any obligation to push the pace today.