How to say july 15, 2015 in spanish (obviously that date already happened so how would that be written as in like past tense, or does it not matter? )

daylight saving time (dst) has been used for more than 100 years. changing the clocks does not create extra daylight, but it causes the sun to rise and set at a one of the aims of dst is to make sure that people's active hours coincide with a german analysis of 44 studies on energy use and dst found a positive