The Muslim holy month of Ramadan runs from 27 May to 24 June in 2017 (Gregorian calendar). During Ramadan, Muslims fast in the daytime while observing other guidelines as well; this is a period for prayer, charity. and contemplation in the Islamic world. Food and drink are taken before daybreak and at sunset, the evening meal usually being a festive occasion for families.
During Ramadan travelers bound for Muslim countries should observe certain guidelines. In some countries, non-Muslims are not obliged to follow the same rules and guidelines, but in others it is illegal not to do so for all. However, in most Muslim countries breaking the fast will be frowned upon and viewed as disrespectful by the local population.
Travelers should also note that the fast tends to impinge on driving standards, especially in the afternoon. As dusk falls, circulation usually increases a lot and public transport and taxi services may become scarce. Patience should be exerted.
Note again that Ramadan is actually enforced on everyone in some countries and that e.g. breaking the fast can be illegal. You should make sure if there are legal imperatives in place at your destination before traveling.
Generally speaking, you should observe the fast in public or in public view. Note that restaurants will mostly be closed as well. Dress modestly and conservatively, and be mindful of the Ramadan even of you are not a Muslim yourself. In some countries wearing shorts, t-shirts or similar attire may attract unwanted attention; in others, it is illegal during Ramadan.
In some countries hotels and restaurants will have sections which cater to non-Muslims and serve food and drink. It is wise to be respectful and not carry food and drink outside these enclosed spaces, even if it is not illegal per se. Businesses may be open on a more erratic basis, and business hours are likely shorter than normal.
As Ramadan ends there is a three-day feast known as Eid. During this period locals travel and visit with families in a traditional celebration. Travel may be somewhat disrupted.