QST: Should the absence of tzdata package affect the performance in any way ?

[sdg002]

Research

• I have searched the [pandas] tag on StackOverflow for similar questions.

• I have asked my usage related question on StackOverflow.

Link to question on StackOverflow

https://stackoverflow.com/search?page=3&tab=Relevance&pagesize=30&q=pandas%20AND%20tzdata%20&searchOn=3

Question about pandas

We are on pandas 1.5.3. We are investigating some performance bottlenecks. At this point, we are not sure where the problem lies. However, we have a consistent pattern of observations.

We noticed that when tzdata==2025.2 was uninstalled, there was a severe degradation in performance (> 10x).

Upon further investigations and eliminations, we arrived at the following matrix:

Good perf-1

pandas==2.2.3
tzdata==2025.2

Good perf-2

pandas==1.5.3
tzdata==2025.2

Bad perf

No tzdata

pandas==1.5.3

Any suggestions ?

Is there any logic in any part of Pandas that relies on tzdata ?

Thanks,
Sau

[sdg002]

Sorry. SFO will not allow me to ask any more questions.

[mroeschke]

tzdata is used as an alternative timezone library compared to pytz. It's hard to answer performance implications without knowing what they are.

Note that pandas 1.5 is no longer supported and tzdata is a required dependency as of pandas 2.0