for me, sunblock is needed for my nose, ears and my shaved scalp. i still tan in the areas covered with sunblock, i just don't burn as i would without sunblock.
here in the south, out door tanning season starts in late march.
i have some deep, dark tan lines from slowly working up to 30 minutes a day, 4 to 5 times a week.
(i am too cheap to pay for tanning machines.)