Dates and times in Python

The dt namespace does the temporal work, on real Date and Datetime types.

import polars as pl

frame = pl.DataFrame({"day": ["2026-07-27", "2026-07-29", "2026-08-02"]})

dated = frame.with_columns(
    pl.col("day").str.to_date().alias("date"),
).with_columns(
    pl.col("date").dt.weekday().alias("weekday"),
    pl.col("date").dt.strftime("%b %d").alias("label"),
    (pl.col("date") + pl.duration(days=7)).alias("next_week"),
)
print(dated)
print(dated.filter(pl.col("date").dt.month() == 8).height)

How it works

1. str.to_date parses text into a Date column.
2. dt.weekday, dt.month and friends extract parts.
3. Date arithmetic uses durations, not raw integers.

Keywords and builtins used here

• as
• print

The run, in numbers

Lines

13

Characters to type

413

Tokens

169

Three-star pace

110 tpm

At the three-star pace of 110 tokens a minute, this run takes about 92 seconds.

Type this snippet

Step 1 of 2 in Time series, step 23 of 32 in Polars.

← Previous Next →

Dates and times in other languages

• HTML
• SQL