Datum Plan
Plan, schedule, track and report your projects: one small, fast app for Windows.
Why Datum Plan
Datum Plan is a complete project scheduling and control tool, written from scratch with its own scheduling engine in Rust. It brings planning, scheduling, resources, costs, progress tracking, reporting and spreadsheets together in one window. You don't need several tools and exports.
- Small and fast. About 3.6 MB to install. It opens in a moment and stays smooth with large plans.
- Everything included. Network logic, resource levelling, earned value, S-curves, dashboards, printing and spreadsheet formulas are all built in.
- Easy to learn. A ribbon, a sheet that works like a spreadsheet, plain-language help, a glossary of planning terms, and templates with real teams and man-hours.
- Private. Plans are
.dplan files on your own computer. The only network call is the update check.
- Dates you can trust. Every release is checked against hand-worked scheduling cases, plan files that carry their own dates, and thousands of random plans and damaged files.
- Always improving. Small releases, installed with one click from inside the app.
Features
Plan
- A task sheet that works like a spreadsheet:
- drag-select ranges and select whole rows and columns;
- copy and paste with other spreadsheets, with Paste Special (values, formats, transpose);
- a fill handle that continues series;
- Sum, Average and Count of the selection;
- fonts, colours, fill and alignment.
- Outline (WBS) with summaries, milestones, recurring tasks, manual or automatic scheduling, inactive tasks and splits.
- Links of every type (Finish-to-Start, Start-to-Start, Finish-to-Finish, Start-to-Finish) with lags and leads in days, hours or percent.
- About 450 fields; rename any column, and hide, unhide, delete or reorder columns with the Columns dialog.
- Formula columns in spreadsheet syntax that refer to other columns, e.g.
=[% Complete]-[Baseline % Complete] or =IF([Finish]>[Baseline Finish],"Late","On time"), with about 400 spreadsheet functions.
- Sheets: spreadsheet tabs inside the plan for your own reports, quantities, estimates and vendor lists. Click cells into a formula, 490 functions suggested as you type, AutoSum, fill and paste that move references, insert and delete rows and columns. They read the plan live by name (
Tasks[Finish], Resources[Country], ProjectFinish, SPI), Plan Data puts a live list of milestones or late tasks in one click, and countries show their flags.
- Your own dashboards: several per plan, made of tiles you lay out: numbers and progress rings from formulas (green or red by a rule), the plan's charts and lists, charts and tables from sheets, and country flags. Templates for a client dashboard, weekly progress and vendors.
- Project Setup walks you through a new plan: details, Activity IDs, calendar, currency, WBS, team and branding. Templates for engineering, EPC, construction, software and research come with people, rates, assignments and costs.
Schedule
- A critical path engine that works to the minute, with working calendars, holidays, task and resource calendars, all constraint types, deadlines and elapsed durations.
- Resource calendars that drive task dates (optional): each person's own working week and leave decide when their work is done; a task finishes when the last person on it does.
- Projects made of plans: a master plan and its subplans, in order and in a hierarchy, with their tabs grouped in one colour and the whole project in the master's Gantt (subplans as rows you can expand); New Subplan, Open All Subplans and Close Project.
- Several plans in tabs, with links between them: a main schedule and its subplans in their own files; a task can wait for a task in another plan, Linked Plans shows what has moved, and Update Links brings every open plan up to date. File › Linked plans (example) opens a four-plan example.
- Longest path, float paths, free and total float, retained logic or progress override, scheduling from the finish.
- Resource levelling (all tasks or a selection), with a preview of which tasks move and the new finish before anything changes, and clearing it again.
- Schedule risk analysis: the plan runs a thousand times with uncertain durations and the risks from the register, to show the chance of finishing by each date (P50, P80, P90), the likely cost, how often each task is critical, and which tasks drive the finish.
- A schedule health check with drill-down to the tasks behind each finding.
Resources and cost
- Work, material and cost resources, with groups, rates over time, overtime, cost per use, availability, and 8-hour days or any calendar you set.
- Man-hours and costs per task, resource and period; resource usage, histograms and overallocation warnings, per person or per trade (in hours or people); Team Planner.
- Fixed costs, expenses, any currency, and cash flow.
Track progress
- Status date, % complete, actual dates, remaining duration, Mark on Track, Update Progress for a whole period, and Close Period with snapshots.
- 11 baselines and the Tracking Gantt: baseline bars under the current bars, the done part solid, and % labels.
- Earned value (SPI, CPI, EAC, TCPI) and earned schedule (SPI(t) and the finish at the current pace), period-by-period comparison, S-curves (planned, actual and forecast) whose actual line follows the progress stored at each period close, and milestone tracking.
- Progress measured by rules of credit (weighted steps such as pulled, terminated, tested) or by installed quantities (200 m of cable, 50 m pulled).
- A look-ahead of the next 2 to 6 weeks with a constraint log (materials, drawings, permits, access, people), showing which tasks are ready to start.
- Manpower by trade: people planned, work done and forecast per week or month.
Report, print and share
- Dashboard with key figures and charts, Progress reports for any week or month with notes and photos, S-curves, and a Report Builder with templates (weekly management, monthly client, schedule health, cost).
- Print to paper or PDF from every view: paper size, orientation, scaling or fit to pages, margins, date ranges, page ranges, headers and footers with your logo and your client's, page numbers and a legend.
- Excel (.xlsx) export keeps formulas and formatting. Also exports to CSV, HTML, iCalendar and JSON, and imports and exports the common project exchange files (XML, XER, PMXML, MPX). Every import ends with a report of anything changed or left out, and whether every task gets the same dates as in the file.
Views
Gantt Chart · Tracking Gantt · Schedule Risk · Look-ahead · Manpower · Network Diagram (whiteboard canvas, legend, WBS bands, mini-map, path highlight) · Calendar · Timeline with a zoom box · Task Usage · Resource Sheet · Resource Usage · Resource Graph · Team Planner · Relationship Diagram · Sheets · Dashboard · Progress · S-Curves · Checks · Risks · Portfolio.
Help when you need it
Tell Me (Ctrl+K) finds any command. Help › Getting Started and a searchable Glossary explain every term. Light, dark or automatic theme.
Install
- Download
DatumPlan-x.y.z-setup.exe from Releases.
- Run it. It installs for your user account, with no administrator rights needed. The installer is not code-signed yet, so on the first install Windows may show "Windows protected your PC". Click More info › Run anyway.
- Later versions install from inside the app: File › Home › Update now, or click the amber Update available badge. Every download is checked against its SHA-256 checksum.
The guide
The Datum Plan Guide walks through everything step by step, with pictures: English (PDF) · 中文 (PDF). In the app: Help › Guide.
Your first plan in five minutes
- File › New and pick a template (or Blank Project), then follow Setup.
- Type task names, durations (
5d, 2w, 0 for a milestone) and predecessors (3, 4SS+2d).
- Indent tasks to build the outline; assign people in the Resource Names column (
Design Engineer[50%]).
- Progress › Set Baseline, then record progress as work happens and open the Tracking Gantt.
- Report › Dashboard or File › Print to share it.
Roadmap
See the changelog for every release and the roadmap for what is next: schedule quality and what-if scenarios, a combined view of linked plans, a shared resource pool across plans, portfolio dashboards, signed installers, and working together on shared plans.
Datum Plan is part of Datum; see its page: https://edgar-mendonca.github.io/Datum/apps/plan. docs/FAMILY.md describes the shared design.
Command line and AI assistants
datum-cli (on the Releases page) works with plans without the window:
datum-cli info plan.dplan # dates, tasks, cost, critical tasks
datum-cli schedule plan.xer --csv # every task with its dates and float
datum-cli ops # the named operations, with examples
datum-cli apply plan.dplan --op '{"Set":{"uid":2,"field":"dur","value":"4d"}}' --save new.dplan
datum-cli export plan.dplan plan.xlsx # any export format
datum-cli risk plan.dplan --runs 2000 # P50, P80, P90 finish
datum-cli mcp is a Model Context Protocol server: an AI assistant can open or start a plan, read the schedule, change it with the same named operations the window uses, run the risk analysis and save it. Nothing is written unless it is asked to save.
Build from source
You need Rust (stable) and Node.js 20+. On Linux, also install libwebkit2gtk-4.1-dev libgtk-3-dev librsvg2-dev.
npm ci
npm run build:ui # build the window (Vite + SolidJS)
cargo run -p datum-plan # run the app
cargo run -p datum-cli -- help # the command line
cargo test --workspace # engine tests (cases, parity files, random plans)
npm run check:ui # type-check the window
node tests_ui/run.cjs # UI tests (Playwright)
npm run build # Windows installer (on Windows)
The engine (scheduling, resources, costs, reports, file formats) is in crates/core; the desktop shell in src-tauri; the window in ui/src. Architecture and decisions are in docs/MEMORY.md.
Feedback
Found a bug or have an idea? Open an issue. The app has the same link under Help › Report an Issue.
Licence
MIT © 2026 Edgar Mendonca. Third-party notices are in NOTICE.
