"If you really like someone, there's no such thing as not having enough time for them."
In any and all relationships that we have in which we care for another person and have some kind of commitment to this person, we have to be willing to sacrifice. Yes sometimes we must give things that we may not always want to give away, and included in this is our time. Time is very important because it is something that once gone will never be given back, but is necessary to give away to people we love in order to best strengthen the bond that we have with them.
Making the time out of our busy days to spend with those that we love is probably the best way to show someone that we care. Life is more about how present you are in somebody else's instead of how much material wealth that you are able or desire to give them. Instead of your relationships being about what you can spend on presents to your loved ones, make it about what you can spend in time with your loved ones, your presence.