This is a very common belief, promoted by many influential figures and media around the world.
It is not completely true, the reduction of carbs helps you to reduce total daily calorie intake. This can create a deficit in calories – A key factor in weight loss. The timing is not as important.
In contrast to eliminating all carbohydrates at night time, some research shows carbs can help with sleep and recovery, although more research is needed on this area.
This may be more truthful, as carbs release the neurotransmitter serotonin, which helps regulate your sleep cycle. Given this information, keeping track of your total calorie intake may be more beneficial.
Based on the health benefits of a sleeping well at night, carbs in the evening may actually be beneficial, especially if you have some problems sleeping.
Everyone is different and so is their daily calorie requirments based on activity/work/exercise intensity. Using a calorie counter is a great tool for keeping track of your daily needs and can be downloaded for free. My Fitness Pal & My Net diary are two of the favourites.