A date is a time on a calendar, and it is typically written as the month and then the day of that month (MM/DD/YY) or day and then the month of the year (DD/MM/YY). A time is typically written as hours and minutes, and different countries set the date and time in different ways. One country may write the date as "January 12, 2017" while another may write the same date as "12/1/2017." The two countries have two different ways of setting their dates.
Date and Time are just concepts that help us understand the flow of days, months, years, etc. They are used in almost everything that we do - from school times to work schedules, to holidays, and even scheduling for birthdays.
The calendar has been around for thousands of years but it was actually born out of religion. This is because it helped people to calculate important dates like religious festivals (Christmas) or major events (the start of the World War).