Working With Timestamp in PHP

Output the current time in timestamp format.

Output March 1, 2025 in timestamp format.

Output December 31 of the current year in timestamp format. The script should work regardless of the year it is run in.

Find the number of seconds that have passed since 13:12:59 on March 15, 2000 until the present moment.

Find the number of whole hours that have passed since 7:23:48 today until the present moment.