Alternatives
Please be aware that different projects may have different design goals (speed, accuracy, data sources, etc.). Please do your own research on which one is the best for your use case.
This page is not a complete list of all alternatives.
See the repos in Lookup Libraries section of evansiroky/timezone-boundary-builder first.
A question on Stack Overflow also: How to get a time zone from a location using latitude and longitude coordinates?.
Speed, memory, and accuracy at a glance
The radar charts below compare popular timezone lookup packages in Go, Python, and Rust on lookup speed, peak memory, and accuracy (wrong-result rate), based on the continuous benchmark results from tz-benchmark. All three axes share logarithmic scales, so further out is better; click a package name below a chart to see its numbers.
The chart data is from the 2026-09-14 snapshot (local Apple M3 Max run), which measured tzf v2.1.1, tzf-rs 2.1.1 and the tzfpy 2.1.0b2 pre-release; see Benchmarks for the full tables. The memory axis is the growth in resident memory over the process baseline once the package has loaded, so it counts the bytes each package adds and not the Go, Rust or Python runtime itself.
Go
- https://github.com/ringsaturn/tzf
- https://github.com/bradfitz/latlong
- https://github.com/evanoberholster/timezoneLookup
- https://github.com/albertyw/localtimezone/
- https://github.com/ugjka/go-tz
- https://github.com/zsefvlol/timezonemapper
Rust
- https://github.com/ringsaturn/tzf-rs
- https://github.com/twitchax/rtz
- https://github.com/huonw/tz-search
- https://github.com/nicholasbishop/zone-detect-rs
- https://github.com/moranbw/spatialtime
Python
- https://github.com/ringsaturn/tzfpy
- https://github.com/jannikmi/timezonefinder
- Please see its comparison with tzfpy: Comparison to tzfpy and a thread in tzfpy’s issue:
ringsaturn/tzfpy#94
- Please see its comparison with tzfpy: Comparison to tzfpy and a thread in tzfpy’s issue:
- https://github.com/pegler/pytzwhere