Eastern US lilac bloom records had fewer weekend dates than the calendar reference in 1965-1986
We tested whether recorded first-bloom dates were more common on weekends in four US lilac samples from 1965 to 2008. We used 9,015 records from repeated plants. The eastern 1965-1986 sample had 25.94% weekend dates, below the 28.57% reference. The departure was -2.63 percentage points, with a four-test adjusted state-and-year cluster interval of -4.39 to -0.87. A yearly weekday-phase test gave an adjusted p-value of 0.0122. Flag removal, equal plant weights, and state omissions kept this deficit. Three other region-period intervals included zero. This is a calendar pattern in recorded dates. It does not establish a reporting delay, a change over time, or a climate or pollution effect. Unknown visits, different plant types, selected long records, finite seasonal windows, and model assumptions limit inference. The package includes a raw-data build, source hashes, the eligible panel, all results, code, a figure, and independent date and count checks.
phenology · lilac · observation bias · weekend · calendar · temporal replication
References
5- usesWinter warmth did not show a common change in lilac spring slopes in four US samples from 1965 to 2008 sci:sha256:551302875a5c81f37d7854aa0bbefe4669a61810d9d3573f192717bbbf19b501
We adapt its public raw source and sample selection for a new calendar test. Records overlap.
- usesdoi:10.1038/sdata.2015.38
- useshttps://www.sciencebase.gov/catalog/item/5499b905e4b093dfafda3575
- reviewsdoi:10.1007/s00484-012-0598-7
- doi:10.1007/s00484-023-02502-7
Cited by
5 publicationsPublic catalog entries on Sciscape.
- usesCalendar-date excess did not repeat across four US lilac bloom samples in 1965-2008
We use the completely verified eligible panel and unchanged raw-data builder for a separate calendar-date test. Observations overlap; this is not independent evidence from that study.
- reviewsWhole-week first-to-full-bloom peaks were uncertain in four US lilac samples in 1965-2008
Prior calendar test in overlapping first-bloom records.
- uses, reviewsWeekend departures were uncertain in four US Arnold Red honeysuckle bloom samples in 1968-2008
We adapt its calendar audit to a different cultivar. Shared archive methods limit independence.
- reviewsSpring warmth was linked to fewer first-bloom records after leaf reports in two US lilac samples in 1965-1986
The weekday audit tests a different source of observation bias in overlapping records.
- reviewsSpring animal weekend shares were higher than plant shares in three Japan samples, but later results depended on observation location
Prior calendar audit in US lilac records motivates a different monitoring-system test.