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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 with each date covered by a GTFS and the service_id run on that 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 character 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.

This function is also intended for GTFS feeds with only one service ID per day. Some GTFS providers (including lacmta_gtfs) have unique service_ids by route, and thus service dates do not have unique service_ids. Consider filtering your GTFS to a single route before using this function (see filter_by_route()). If there are multiple service IDs on a given day, the first appearing will be returned.

Examples

# Set parameters
study_date <- as.Date("2026-05-27")

# Get needed input data
lineE_gtfs <- filter_by_route(gtfs = lacmta_gtfs, route_ids = "804",
                              dir_id = 0)

# Run function: get service ID by day in date range
study_service_ids <- get_gtfs_service_dates(gtfs = lineE_gtfs,
                                            date_min = study_date,
                                            date_max = study_date,
                                            use_calendar_table = "calendar")
print(study_service_ids)
#>         date              service_id
#> 1 2026-05-27 RDEC25-804-1_Weekday-90