Condoms are often used in sex education programs, because they have the capability to reduce the chances of pregnancy and the spread of some sexually transmitted diseases when used correctly. A recent American Psychological Association (APA) press release supported the inclusion of information about condoms in sex education, saying "comprehensive sexuality education programs... discuss the appropriate use of condoms", and "promote condom use for those who are sexually active."
In the United States, teaching about condoms in public schools is opposed by some religious organizations. Planned Parenthood, which advocates family planning and sex education, argues that no studies have shown abstinence-only programs to result in delayed intercourse, and cites surveys showing that 76% of American parents want their children to receive comprehensive sexuality education including condom use.
The prevalence of condom use varies greatly between countries. Most surveys of contraceptive use are among married women, or women in informal unions. Japan has the highest rate of condom usage in the world: in that country, condoms account for almost 80% of contraceptive use by married women. On average, in developed countries, condoms are the most popular method of birth control: 28% of married contraceptive users rely on condoms. In the average less-developed country, condoms are less common: only 68% of married contraceptive users choose condoms.
This standard defines for most of the countries and dependent areas in the world:
a two-letter (ISO 3166-1 alpha-2)
a three-letter (ISO 3166-1 alpha-3), and
a three-digit numeric (ISO 3166-1 numeric) code.
The two-letter codes are used as the basis for some other codes or applications, for example,
for ISO 4217 currency codes and
with deviations, for country code top-level domain names (ccTLDs) on the Internet: list of Internet TLDs.
For more applications see ISO 3166-1 alpha-2.
The primary practical use of a calendar is to identify days: to be informed about or to agree on a future event and to record an event that has happened. Days may be significant for agricultural, civil, religious or social reasons. For example, a calendar provides a way to determine when to start planting or harvesting, which days are religious or civil holidays, which days mark the beginning and end of business accounting periods, and which days have legal significance, such as the day taxes are due or a contract expires. Also a calendar may, by identifying a day, provide other useful information about the day such as its season.
Calendars are also used to help people manage their personal schedules, time and activities, particularly when individuals have numerous work, school, and family commitments. People frequently use multiple systems, and may keep both a business and family calendar to help prevent them from overcommitting their time.
Calendars are also used as part of a complete timekeeping system: date and time of day together specify a moment in time. In the modern world, timekeepers can show time, date and weekday.