It's a common misconception that night vision scopes can't be used in daylight. While it's true that they're not as effective in daytime conditions, they can still be used to good effect. The human eye is less sensitive to light in the green part of the spectrum, which is why night vision devices work by amplifying available light in this wavelength range. This means that while a night vision scope may not provide the same level of clarity and detail as it would in low-light conditions, it can still be used to good effect during the day.
One thing to bear in mind is that using a night vision scope during the day can put strain on your eyes. This is because you're effectively looking through a green filter, which can make objects appear blurry or distorted. It's therefore important to take regular breaks when using a night vision scope during daylight hours.