Naturally, that depends on how fast you can count.

But if you can count from 1 to 100 in one minute, and you keep counting every minute, without stopping, for eight hours every day (taking time off to eat, sleep, and go to school), you would reach 1,000,000 in 20 days, 6 hours, and 40 minutes, or almost 3 weeks.

If, however, you give up eating, sleeping, and school, and just count every minute of every hour of every day, you would reach 1,000,000 in 6 days, 22 hours, and 40 minutes, almost 1 week.