getting an error trying to download pictures

[datayoda]

DateTime::__construct(): It is not safe to rely on the system's timezone se
ttings. You are required to use the date.timezone setting or the date_def
ault_timezone_set() function. In case you used any of those methods and you
are still getting this warning, you most likely misspelled the timezone id
entifier. We selected the timezone 'UTC' for now, but please set date.timez
one to select your timezone.