I don't think there is any such thing as 'appropriate time to give a gift'. I don't think individuals should put any restrictions for expressing themselves. Personally, I do not believe in Valentines Day for expressing my feelings towards my love. If you ask me, every day should be a Valentines Day where the couples in relationship should express their appreciation and love. Love is not about costly gifts, it's more about caring for each other, respecting and appreciating each other. Any gesture done from the heart for the partner is a good gift in itself. If one values his/her relationship, make a point not to forget to make your partner feel special on Birthdays, Anniversaries etc.