There are 52 weeks in 2014. A week starts on a Monday and ends on a Sunday. The first week of 2014 began on Dec. 30, 2013 and ended on Jan. 4, 2014. The last week of 2014 begins on Dec. 22, 2014 and ends on Dec. 28, 2014.
There are 365 days in a year. Every four years is a leap year, which has 366 days. Century years, such as 2000, are leap years only if they are divisible by 400. One week has seven days. So one calendar year has either 52 weeks plus one day, or 52 weeks plus two days.