LoginSign Up
← Back to all sparks
T

tzdb

DEVOPS
Velocity0.0

Bundles the IANA time zone database for consistent date-time handling in R

github.com/r-lib/tzdb ↗

A package whose entire job is to ship someone else's database on time.

time-zonescpp-headerstidyversedependencydata-updates
◆Current state
tzdb exists to bundle the IANA time zone database and Howard Hinnant's date library, and to expose both as C++ headers other R packages can compile against. That header interface, added in 0.1.1, is what clock, readr and the tidyverse datetime stack are built on. Every release since has been the same three-line shape: bump the time zone database, bump the embedded date library, raise the minimum R version to whatever the tidyverse has standardised on.
◆Where it's heading
There is no roadmap here and there does not need to be one. The package's release cadence is set by IANA publishing new time zone rules and by upstream date library commits, which is the honest description of its trajectory: it is a distribution vehicle, and its quality is measured in how quickly a new tzdb release reaches CRAN after IANA cuts one. The R version floor rising to 4.0.0 is the only decision in the last several releases that tzdb made itself.
◆Prediction
Expect the next release to be another database bump with a date library SHA and nothing else, timed to whenever IANA publishes.

◆Recent moves

  1. 1y ago

    Time zone database updated to 2025a; R 4.0.0 required

    Updates the time zone database to 2025a and the embedded date library, and raises the floor to R 4.0.0 and cpp11 0.5.2. The database bump is the payload — new IANA rules reach every package that compiles against these headers.

    View source ↗
  2. 1y ago

    Time zone database updated to 2023c

    Ships the 2023c time zone database and a date library update, with the R floor moved to 3.5.0 to match tidyverse standards. Released six days before 0.5.0, which then superseded the database version outright.

    View source ↗
  3. 4y ago

    2022a database; cpp11 floor raised for unwind protection

    The 2022a database plus a date library refresh, and a cpp11 0.4.2 floor pulled in specifically for an unwind protection fix. The cpp11 requirement is the interesting part — a correctness fix in the C++ interface layer propagating down as a hard dependency bound.

    View source ↗
  4. 4y ago

    2021e database; fix Windows Unicode path lookup

    The 2021e database and a date library update, plus a Windows fix where the database could not be located if its path contained Unicode characters. That bug would have made the package silently useless for a subset of Windows users.

    View source ↗
  5. 5y ago

    tzdb 0.1.2

    A single line: the embedded date library was updated. No database bump, no user-facing change.

    View source ↗
  6. 5y ago

    tzdb exposes the date library as C++ headers

    ⚡ SPARK

    The release that turned tzdb from a data package into a compile-time dependency by exposing the date library as C++ headers and callables. Everything the package has shipped since is a refresh of what this release made consumable.

    View source ↗