The ideal time to book a Cairo day tour depends on several factors, including the time of year you plan to visit, the popularity of the tour, and your own preferences. Here are some general guidelines:

Peak Tourist Season: If you plan to visit Cairo during the peak tourist season, which is typically from October to April when the weather is more comfortable, it's advisable to book your day tour well in advance. This is especially important for popular tours and attractions, as availability may be limited.

Advance Booking: As a general rule of thumb, booking your Cairo day tour at least a few weeks to a few months in advance is a good idea. This allows you to secure your preferred tour date and time, especially if you have specific sites or activities in mind.

Last-Minute Options: While advance booking is recommended, Cairo also offers many tours on relatively short notice. If you have flexibility in your schedule and are open to available options, you can often find day tours with a day or two of notice, especially during the less busy travel months.

Specialty Tours: If you're interested in specialty tours, such as hot air balloon rides or camel treks, it's best to book these in advance, as they often have limited availability and require planning.

Group Size: The size of your group can also impact booking. Larger groups may need to secure their spots further in advance, while smaller groups or solo travelers may have more flexibility.

Tour Operator Policies: Check the booking policies of the tour operators you're interested in. Some may offer discounts for booking early, while others may have flexible cancellation policies.

Local Holidays and Events: Be aware of local holidays and events that could affect tour availability. During major holidays and festivals, tours may be in higher demand, so it's best to book early.

Personal Preferences: If you have specific preferences for your day tour, such as a particular guide, language, or itinerary, booking in advance allows you to make those arrangements.