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Get a dataframe of all service dates and their service IDs from a GTFS.

Source: R/gtfs_helpers.R
get_gtfs_service_dates.Rd

This function returns a dataframe of each date covered by a GTFS and the service_id run on this date. This data is extracted from the calendar.txt and calendar_dates.txt files, depending on how the GTFS is structured. See Details for a discussion.

Usage

get_gtfs_service_dates(
  gtfs,
  date_min = NULL,
  date_max = NULL,
  use_calendar_table = "calendar"
)

Arguments

gtfs

A tidygtfs object.

date_min

Optional. The starting (earliest possible) Date object for the returned dataframe. Default is NULL, where the earliest date in the GTFS will be used.

date_max

Optional. The ending (latest possible) Date object for the returned dataframe. Default is NULL, where the latest date in the GTFS will be used.

use_calendar_table

Optional. Should the GTFS's calendar.txt or calendar_dates.txt be used for the feasible date range? Must be "calendar" or "calendar_dates". Default is "calendar".

Value

A dataframe with Date column date, and numeric column service_id.

Details

The GTFS standard allows for two different structurings of calendar.txt and calendar_dates.txt:

  • Standard service in calendar.txt, with exceptions in calendar_dates.txt. Here, calendar.txt will list the standard service ID by weekday (e.g., Monday, Tuesday, etc.), and calendar_dates.txt lists specific dates which are exceptions to this. In this scenario, get_gtfs_service_dates() will get enumerate all weekdays and dates in calendar.txt, and assign the correct service_id to it, depending on if the date is listed as an exception in calendar_dates.txt.

  • All dates of service are enumerated in calendar_dates.txt, and calendar.txt is not used. In this scenario, get_gtfs_service_dates() will simply filter, clean, and return this table.

Use the input parameter use_calendar_table to control which method to use. If use_calendar_table = "calendar", the former method will be used; if use_calendar_table = "calendar_dates", the latter will be used. To restrict the date enumeration to only a specific window, set date_min and date_max.

Examples

# Set parameters
trb_start <- as.Date("2026-01-11")
trb_end <- as.Date("2026-01-15")

# Run function: get service ID by day in date range
trb_service_ids <- get_gtfs_service_dates(gtfs = wmata_gtfs,
                                          date_min = trb_start,
                                          date_max = trb_end,
                                          use_calendar_table = "calendar")
print(trb_service_ids)
#>         date service_id
#> 1 2026-01-11          2
#> 2 2026-01-12          9
#> 3 2026-01-13          9
#> 4 2026-01-14         10
#> 5 2026-01-15          9