It will depend upon your specific state's laws regarding the expiration of inspection stickers however in general most states inspection stickers do not expire until the end of the month punched.
For example Virginia State Police note that an inspection sticker expires the last day of the month, regardless of whether it is a weekday (Monday-Friday) or weekend (Saturday-Sunday).
The New York State Department of Motor Vehicles states that inspection stickers expire at the end of the month punched out on the sticker. So if you are from NYS then you would have until the end of November to get your car inspected and new inspection sticker placed on your vehicle. It appears at some point in time they had an extra hole to punch for which part of the month the inspection sticker expired however the NYS DMV states that the DMV has returned to the old policy.
The NYS DMV will continue to use the type of sticker tat has dates listed for 1 - 10, 11 - 20 and 21 -31 however, the inspection stations have instructions to punch only the month of expiration, not the dates across the top of the sticker. The stickers will be revised at some point in 2007 to remove the dates.
In New York if the inspection sticker on your vehicle has expired in the past 60 days, you can receive a fine of $25 to $50. If the inspection sticker is expired more than 60 days, the fine is between $50 and $100. If there is no inspection sticker, the fine is between $50 and $100. Mandatory state surcharges of up to $55 are added to the fine.
To find out if in your state the inspection sticker expires at the beginning of the month or at the end of the month contact an inspection station or the Department of Motor Vehicles.