### Question
Can you define what calendar year means?


### Answer
**Calendar year** is defined as the following in *26 CFR § 1.441-1T*:

> a period of 12 months ending on December 31. A taxpayer who has not established a fiscal year must make his return on the basis of a calendar year

#### Citation:
  - *26 CFR § 1.441-1T*
  - Heading: **Title 26—Internal Revenue > PART 1—INCOME TAXES > CHAPTER I—INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY(CONTINUED)**

