Event Timeline — plotnine

A timeline visualization that displays events and milestones along a temporal axis. Events are represented as points or markers with accompanying labels, making it easy to understand the sequence and timing of events. This plot type excels at showing chronological progressions and is particularly effective for communicating project phases, historical events, or any time-ordered sequence of occurrences.

Event Timeline rendered with plotnine

Python source (plotnine)

""" anyplot.ai
timeline-basic: Event Timeline
Library: plotnine 0.15.4 | Python 3.13.13
Quality: 95/100 | Updated: 2026-05-11
"""

import os
import sys
from pathlib import Path


# Remove current directory from path to avoid importing local plotnine.py
current_dir = str(Path(__file__).parent)
sys.path = [p for p in sys.path if p != current_dir and p != ""]

import pandas as pd
from plotnine import (
    aes,
    element_blank,
    element_line,
    element_rect,
    element_text,
    geom_point,
    geom_segment,
    geom_text,
    ggplot,
    labs,
    scale_color_manual,
    scale_y_continuous,
    theme,
    theme_minimal,
)


# Theme tokens
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"

# Okabe-Ito palette (first series is always #009E73)
IMPRINT = ["#009E73", "#C475FD", "#4467A3", "#BD8233"]

# Data - Software development project milestones with varied timing
data = {
    "date": pd.to_datetime(
        [
            "2024-01-08",
            "2024-02-15",
            "2024-03-08",
            "2024-04-12",
            "2024-05-20",
            "2024-06-10",
            "2024-07-18",
            "2024-08-05",
            "2024-09-22",
            "2024-10-15",
            "2024-11-08",
            "2024-12-20",
        ]
    ),
    "event": [
        "Project Kickoff",
        "Requirements Complete",
        "Architecture Review",
        "Backend Alpha",
        "Frontend Alpha",
        "Integration Testing",
        "Beta Release",
        "User Acceptance",
        "Performance Tuning",
        "Security Audit",
        "Release Candidate",
        "Production Launch",
    ],
    "category": [
        "Planning",
        "Planning",
        "Planning",
        "Development",
        "Development",
        "Testing",
        "Development",
        "Testing",
        "Development",
        "Testing",
        "Release",
        "Release",
    ],
}

df = pd.DataFrame(data)

# Alternate label positions above and below the axis
df["y_offset"] = [1 if i % 2 == 0 else -1 for i in range(len(df))]
df["y_point"] = df["y_offset"] * 0.35
df["y_label"] = df["y_offset"] * 0.65

# Split dataframe for alternating text positions
df_above = df[df["y_offset"] == 1].copy()
df_below = df[df["y_offset"] == -1].copy()

# Category colors - using Okabe-Ito palette
category_colors = {
    "Planning": IMPRINT[0],
    "Development": IMPRINT[1],
    "Testing": IMPRINT[2],
    "Release": IMPRINT[3],
}

# Create timeline plot
plot = (
    ggplot(df, aes(x="date", y=0))
    # Vertical connector lines from axis to points
    + geom_segment(aes(x="date", xend="date", y=0, yend="y_point"), color=INK_SOFT, size=0.8, alpha=0.5)
    # Timeline axis line
    + geom_segment(
        aes(x=df["date"].min() - pd.Timedelta(days=20), xend=df["date"].max() + pd.Timedelta(days=20), y=0, yend=0),
        color=INK_SOFT,
        size=1.5,
    )
    # Event points on the timeline
    + geom_point(aes(x="date", y="y_point", color="category"), size=5)
    # Event labels above the axis
    + geom_text(data=df_above, mapping=aes(x="date", y="y_label", label="event"), size=11, color=INK, va="bottom")
    # Event labels below the axis
    + geom_text(data=df_below, mapping=aes(x="date", y="y_label", label="event"), size=11, color=INK, va="top")
    # Styling
    + scale_color_manual(values=category_colors)
    + scale_y_continuous(limits=(-1.2, 1.2))
    + labs(title="timeline-basic · plotnine · anyplot.ai", x="Project Timeline 2024", y="", color="Phase")
    + theme_minimal()
    + theme(
        figure_size=(16, 9),
        plot_background=element_rect(fill=PAGE_BG, color=PAGE_BG),
        panel_background=element_rect(fill=PAGE_BG, color=PAGE_BG),
        plot_title=element_text(size=24, ha="center", color=INK),
        axis_title_x=element_text(size=20, color=INK),
        axis_text_x=element_text(size=16, color=INK_SOFT),
        axis_text_y=element_blank(),
        axis_ticks_major_y=element_blank(),
        axis_line_y=element_blank(),
        panel_grid_major_y=element_blank(),
        panel_grid_minor_y=element_blank(),
        panel_grid_major_x=element_line(color=INK_SOFT, alpha=0.1, size=0.3),
        panel_grid_minor_x=element_blank(),
        legend_background=element_rect(fill=ELEVATED_BG, color=INK_SOFT),
        legend_title=element_text(size=18, color=INK),
        legend_text=element_text(size=16, color=INK_SOFT),
        legend_position="bottom",
    )
)

# Save
plot.save(f"plot-{THEME}.png", dpi=300, verbose=False)

Part of Event Timeline on anyplot.ai.

Other implementations