strtotime function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC) Let's write the current date in the Unix timestamp format: echo strtotime("now"); This is how you can add three days to the current time echo strtotime("+3 day") Converting the Unix timestamp to the current date and time echo...