Dogs are generally allowed on many beaches in the Netherlands from mid-October or early October until May, often allowed off-leash during this period. During the summer months (roughly May to September), dogs are often restricted or only allowed on certain parts of the beach during early morning and late evening hours, or in designated dog-friendly zones. For example, at some beaches dogs can roam off-leash from September to May, while during summer they may be allowed only between certain hours like 7 PM to 9 AM or in designated dog-only areas. Some beaches forbid dogs during peak daytime hours in summer to protect wildlife and for the comfort of other beachgoers. Here are some examples of specific timing on popular Dutch beaches:

• Wassenaar Beach: Dogs off-leash from September to May; restricted in summer.
• Katwijk Beach: Dogs allowed April 1 to October 1 only between 7 PM and 9 AM on most parts; designated dog-friendly beach open year-round.
• Noordwijk Beach: Large dog beach where dogs off-leash all year; on other parts off-leash only Sept 1 to June 1.
• Scheveningen: Dogs not permitted May 15 to October 1 except in specific zones; allowed off-leash outside this period.
• Zandvoort Beach: Dogs allowed all day Oct 1 to May 1; limited hours in high season May to Sept (before 9 AM and after 7 PM).

Dog owners should also always check for local rules about leashing, cleaning up after dogs, and seasonal breeding restrictions in dunes. This summary is mainly about the Netherlands, but similar rules exist in many other countries, where dogs are typically banned or limited on beaches during busy summer months for safety and hygiene reasons.