What is week?

A week is a unit of time equal to 7 days. It is the standard cycle for work schedules, recurring events, sports seasons, and planning in most cultures worldwide.

Real-world uses

Weeks structure work schedules, school timetables, pregnancy tracking (40 weeks), and agile software development sprints. Pay periods are often weekly or biweekly, and epidemiologists report disease incidence in weekly intervals.

History

The seven-day week has ancient origins, adopted by the Babylonians and later by the Romans, who named days after celestial bodies. It became entrenched in Western culture through the Jewish Sabbath tradition and was formalized in the Roman calendar.

Common mistakes

Assuming a month is exactly 4 weeks—most months are 4 weeks plus 2 or 3 days. Also, different cultures start the week on different days (Sunday in the US, Monday in ISO 8601 and most of Europe).

What is century (100 yr)?

A century is a unit of time equal to 100 years. It is used in historical analysis, long-term demographic and climate projections, and describing spans of civilizational or geological time.

Real-world uses

Centuries are used in historical periodization (e.g., "the 19th century"), long-term climate modelling, geological timeframes, and demographic trend analysis. Architectural preservation classifies buildings by the century of their construction.

History

The word "century" comes from the Latin "centuria," meaning a group of one hundred, used by the Romans for military units of approximately 100 soldiers. Its application to 100-year periods became common in European historical writing.

Common mistakes

The most common error is off-by-one: the 21st century began on January 1, 2001, not 2000, because there was no year zero. Also, confusing centuries with millennia (1,000 years) in historical discussions.

When is this conversion used?

Converting week to century (100 yr) is useful in the time domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 week = 0.00019178 century (100 yr)

1 century (100 yr) = 3.153600e+09 second

How to convert week to century (100 yr)

To convert week to century (100 yr), multiply the value by 0.00019178.

To convert century (100 yr) back to week, multiply by 5,214.28571429.

Measurement standards

The SI second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom, maintained by the BIPM and national metrology institutes worldwide.

Did you know?

Earth's rotation is gradually slowing due to tidal friction with the Moon. To keep atomic time aligned with solar time, "leap seconds" have been inserted 27 times since 1972 — though they are scheduled to be abolished by 2035.

Quick reference: week to century (100 yr)

weekcentury (100 yr)
0.10.00001918
0.50.00009589
10.00019178
20.00038356
50.0009589
100.00191781
250.00479452
500.00958904
1000.01917808
2500.04794521
5000.09589041
1,0000.19178082

Common values

weekcentury (100 yr)
Blink of an eye4.960317e-07 week9.512938e-11 century (100 yr)
Average pop song0.00034722 week6.659056e-08 century (100 yr)
Feature film0.01190476 week0.00000228 century (100 yr)
One work day (8 hrs)0.04761905 week0.00000913 century (100 yr)
One calendar year52.14285714 week0.01 century (100 yr)