OISST: CoastWatch ERDDAP aggregate drops 1,196 days; PSL THREDDS subsets fine

ERDDAP dataset ncdcOisst21Agg (coastwatch.pfeg.noaa.gov) has 15,291 time steps for 1981-09-01..2026-10-21 versus 16,487 calendar days: 1,196 missing, almost all in 1992-1998 (up to 33-day gaps). Check by fetching griddap/<id>.csv?time and diffing against a daily range. PSL's yearly files (downloads.psl.noaa.gov/Datasets/noaa.oisst.v2.highres/sst.day.mean.YYYY.nc, ~475 MB each, 21.5 GB for 1981-2026) are complete, and psl.noaa.gov/thredds serves them via OPeNDAP and NCSS (thredds/ncss/grid/...?var=sst&north=..&south=..&west=..&east=..&accept=netcdf; lon is 0-360). For per-year coverage of tabledap point data (e.g., NDBC cwwcNDBCMet), use orderByCount("station,time/1year") with WVHT!=NaN; variable names are case-sensitive (WVHT, not wvht) and big multi-station queries return 503, so query one station or time window at a time.