Why is Premium in the crate (Silver Shop) shown as a big number (4320)?

The Premium reward inside the crate (Silver shop) is displayed in minutes, not in days or seconds. Divide by 1440: 1440 = 1 day, 4320 = 3 days, 10080 = 7 days, 43200 = 30 days. The Premium you win is credited in full - you can check the remaining time in your profile.