These are normally open Monday to Friday from 0800 – 1900 usually with a two hour break for lunch between 1200 and 1400. In smaller towns and villages they may close at 1600. Saturdays they are generally open from 0800 until noon. The post office in our village is only a 100 metres or so away from the house. Head for the Vival small supermarket and then walk straight across the cross roads and it's on your left.
Most public phone accept pre-paid cards or credit cards rather than coins. Pre-paid cards can be bought from post offices, many tabacs and newsagents. If a phone box has a blue bell that means you can receive calls there but the phone does not ring – keep an eye on the message screen to know when you are being called.
To call to France from you dial 33 plus the nine digit number omitting the initial 0.
Mobile phones seem to work throughout France with better coverage we’ve found than in the UK. Roaming charges are more reasonable now (2014) than before but we find it helpful to set all phones and tablets to 'roaming off' and connect them to the house wifi to save unexpected bills!