The DOI matches its Crossref record; 1 of the 1 references it cites were found in a registry or an index; none of the 3 sources its claims cite is checked for support yet.
Letters to the editor: a machine algorithm for processing calendar dates
Open accessAbstract
No abstract available.
Overview
Integrity signals
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Cites
Statistics
Verification
Claims the paper makes
0 Valid · 2 Not valid · 3 Not checked · 19 Own results and interpretations
A result the paper states — it cites no source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“So if I = 1970, J = 1, and K = 1, then the algorithm gives JD = 2440588.”
plainstates a cause- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: unclear — It is unclear whether the paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“Clearly, the interval between any two calendar dates (on the Gregorian Calendar) can be found by obtaining the Julian Date for each, and finding the difference.”
boostedstates a cause- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“The difference shows up when the grammar in question has a production whose right side consists of one nonterminal symbol.”
plainstates a cause- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“It may not be obvious that the two definitions are not equivalent.”
hedged- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
A conclusion the paper draws from its own results — it cites no other source for it, so there is none to check. The quote shows it is in the paper.
In the paper
“If Feldman and Gries's definition is used, a parse may reach a state where there are no prime phrases and hence the parse cannot be continued.”
§ A Machine Algorithm for Processing Calendar > S ~ aU1b Ui ~ U~ U~ b
hedgedstates a possible cause- Asserted: passes — The authors put it forward as true.
- Checkable: passes — It can be checked against evidence.
- Load-bearing: passes — The paper’s conclusions depend on it.
- Based: passes — The paper gives a reason why it holds.
- Probably not a substantial claim. 18
- It may state two separate claims as one. 3
Citations
Cites
The publisher hasn’t deposited this paper’s reference list.
Research works printed but not linked: 1
- [2]2. MORRISON, DONALD n. Letter to the Editor. Comm. ACM] 11, 3 (Mar. 1968), 150.
Cited by
Blanco-Muriel, M., Alarcón-Padilla, D. C., López-Moratalla, T., & Lara-Coira, M. (2001) · Solar Energy · doi:10.1016/s0038-092x(00)00156-0 · Cited by 397
Orbital Edge Computing: Nanosatellite Constellations as a New Class of Computer System
Denby, B., & Lucia, B. (2020) · Proceedings of the Twenty-Fifth International Conference on Architectural Support for Programming Languages and Operating Systems · doi:10.1145/3373376.3378473 · Cited by 273
“To compare different points in the Gregorian calendar, cote converts each date and time to the equivalent Julian date [29].”
MethodDobson spectrophotometer 83: A standard for total ozone measurements, 1962–1987
Komhyr, W. D., Grass, R. D., & Leonard, R. K. (1989) · Journal of Geophysical Research Atmospheres · doi:10.1029/jd094id07p09847 · Cited by 147
Blanc, P., & Lucien Wald, A. (2012) · Solar Energy · doi:10.1016/j.solener.2012.07.018 · Cited by 143
MeteoIO 2.4.2: a preprocessing library for meteorological data
Bavay, M., & Egger, T. (2014) · Geoscientific model development · doi:10.5194/gmd-7-3135-2014 · Cited by 140
Metadata
- Authors
- Fliegel, H. F., & van Flandern, T. C.
- Affiliations
- Georgetown University (US)
- U.S. Naval Observatory, Washington, D.C.
- Venue
- Communications of the ACM
- Published
- 1968-10
- Volume
- 11
- Issue
- 10
- Pages
- 657
- ISSN
- 0001-0782 (ISSN-L)
- 1557-7317
- OpenAlex
- W2091953806
- Cited by
- 25
- References
- 0
- Citations by year
- 2026: 1 · 2022: 1 · 2020: 2 · 2018: 1 · 2017: 1 · 2016: 1 · 2014: 2 · 2012: 2
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Communications of the ACM (publishedVersion)
- Topics
- Physical Sciences › Mathematics › Theoretical Computer Science › Algorithms and Data Compression
- Physical Sciences › Computer Science › Software › Engineering and Information Technology
- Physical Sciences › Computer Science › Software › Logic, programming, and type systems
- Keywords
- date arithmetic
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
A language model drew the claims from the paper on 2026-10-11, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).
A second model labelled each claim on 2026-10-11 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
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How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Letters to the editor: a machine algorithm for processing calendar dates. https://app.cochat.ai/papers/10.1145/364096.364097
- The paper
- Fliegel, H. F., & van Flandern, T. C. (1968). Letters to the editor: a machine algorithm for processing calendar dates. Communications of the ACM. https://doi.org/10.1145/364096.364097
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
