Pascal MIQUET wrote:
> > Atomic time reception.
>
> On which Transmitter

In the UK, the Rugby 60kHz time signal.
My (shop-bought, 25 UKP) alarm clock receives this,
checking time every hour to save energy. 3V operation.

In mainland Europe, Germany transmits the DCF-77 signal.
The (expensive!) Junghans watches and clocks receive this.

There's another transmitter in the USA.

> an international compatibility should be great,Most stuff is for one system or
 another.

Is this to be battery operated with a PIC?
If so you will need technique to sleep most of the time
but wake on keypresses.
Asleep = 3uA, Awake at 4MHz = 2mA for PIC16C55