apply_lag               Apply time-indexed lags to an exposure series
assign_iso_week         Assign ISO 8601 week and year
assign_season           Assign a season label
build_moving_average    Build moving-average exposure windows
complete_daily_grid     Build a complete daily grid
impute_weekly_mean      Impute missing daily values with the ISO-week
                        mean
pollen_demo             Synthetic daily pollen counts from two
                        monitoring sites
