Weather Working Days (W.W.D.) are days that are suitable for outdoor work, not interrupted by weather conditions that prevent such activities. This term is commonly used in shipping contracts and maritime operations:

Chartering and Shipping: In charter party agreements, weather working days are used to define the days on which cargo operations (like loading and unloading) can be carried out without interruption due to adverse weather.
Calculating Laytime: It’s crucial for calculating laytime, the time allowed for loading or unloading a ship before demurrage (a charge for delays) is applied.

Read More:

What is Yard Storage?