Read this book even if you don't normally read sci-fi. Accounts of time travel are enhanced by philosophical ponderings on decision making, chance and our indisputable mortality.
He started to turn the watch in his hand, looking for the latch that would open the lid. 'Are you sure you want to open it?' she asked quietly. He found the latch but did not touch it. 'Shouldn't I?'.
'No, if you're not ready for a time gift.'
'What kind of time gift could I receive?'
'One that would be able to change your whole life.'