While writing an article on Library and Information Science Journals published in India I was faced with terminology problem for defining periodicity/frequency of issues. Tried Googling but did not get clarity…Infact ended up getting more confused.
Bi-weekly and Semi-weekly is the same – periodicity being twice a week as per Google featured snippets. Biweekly means once every two weeks or twice a week! How is once every two weeks (1 issue in 15days) and twice a week is (2 issues in 7days) same?
Source: https://www.google.co.in/?gfe_rd=cr&ei=SV_qV-rcE4OCoAP68oSwCA#q=semi+weekly
So requested a couple of senior LIS professionals (Dr A L Moorthy & Dr P Divakar) who kindly explained and made it clear! Sharing the same with followers of my blog!
The ‘frequency of publication’ varies from country to country, perhaps depending on British English or American English.
Commonwealth Countries (like Australia, New Zealand, India) generally follow the British English. In India bi-weekly means twice a week but in North America bi-weekly is once in 2 weeks. (Example: Indian Railway Time table, a bi-weekly train runs two times in a week)
It is observed that America dominates the scholarly environment, hence American conventions and definitions on terms like periodicity/frequency will be followed as is given below:
S No | Abbreviation | Periodicity | Frequency | Number |
1. | d | Daily | once per day | 365/12 |
2. | i | ——– | three times per week | 156/12 |
3. | c | Semi-Weekly | two times per week (‘half of a week’) | 104/12 |
4. | w | Weekly | once per week | 52/12 |
5. | j | ——– | three times per month | 36/12
|
6. | e | Bi-Weekly | every two weeks | 26/12
|
7. | s | Semi-Monthly = Fortnight | two times per month (‘half of a month’) | 24/12 |
8. | m | Monthly | once per month | 12/12 |
9. | b | Bi-Monthly | every two months | 6/12 |
10. | q | Quarterly | four times per year | 4/12 |
11. | t | ——– | three times per year | 3/12 |
12. | f | Semi-Annual = Bi-Annual | two times per year (‘half of a year’) | 2/12 |
13. | a | Annual | once per year | 1/12 |
14. | g | Biennial | every two years | 1/24 |
15. | h | Triennial | every three years | 1/36 |
16. | z | ——– | KNOWN: other frequencies (quadrennial – every four years, quinquennial – every five years, etc.) | 1/48, 1/60 etc |
17. | k | Irregular | known to be so (no determinable frequency) | |
18. | u | ——– | UNKNOWN other frequencies |
Request all LIS professionals to read it and get in touch with me at AchalaMunigalRao@gmail.com if there is any discrepency found.
Acknowledgements:
- Dr P Divakar Former Librarian, CCMB, Hyd
- Dr A L Moorthy, Former Director-DESIDOC & Chief Consultant (Inf Sci), BrahMos Aerospace, Hyd
Source: http://www.libraries.rutgers.edu/rul/staff/dts/holdings_rec_mgt/irism_freqcode.html

Terminology Alert: Periodicity/Frequency of Issues in Journals by Dr Achala Munigal is licensed under aCreative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
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June 19, 2016 at 2:12 pm |
The post is quite enlightening…LIS professionals (in India) have long stopped giving attention to such details, unfortunately. Good one.
Best,
Rupesh
June 26, 2016 at 7:03 am |
Thank you Rupeshji.
June 2, 2017 at 11:29 am |
Reblogged this on IndiaLibraries.
August 5, 2020 at 10:34 am |
Useful information sir.