Time-Based Data Analysis

You want to answer questions like "how much did revenue change since last quarter?" or "what did this data look like before the update?" -- without maintaining separate copies of your spreadsheet for each time period.

GeoSheet's Time Warp feature records every cell edit with a timestamp. You can browse your data's history visually, compare any two points in time with formulas, and restore past states -- all within a single spreadsheet that stays current.

Worked Example: Tracking Monthly Sales Changes

You have a sales tracking sheet that gets updated regularly:

Step 1: Enable Time Warp

1. Click the Time Warp icon (clock) in the toolbar
2. The Time Warp panel appears below the toolbar with a timeline slider

Once enabled, all cell edits are recorded with timestamps going forward.

Step 2: Compare to a past date

After a month of updates, you want to see how sales changed. In column C, add:

=B2 - B2@"2026-03-01"

This subtracts the value of B2 on March 1st from its current value. Copy down to C5 for all regions.

Step 3: Calculate percentage change

=ROUND((B2 - B2@"2026-03-01") / B2@"2026-03-01" * 100, 1)

Returns the percentage change since March 1st. Combine with IF to flag significant changes:

=IF(ABS((B2 - B2@"2026-03-01") / B2@"2026-03-01") > 0.1, "Review", "OK")

Step 4: Browse history visually

Drag the timeline slider to scrub through time. The grid updates instantly to show the state of all cells at the selected timestamp. You can see exactly when a value changed and what it was before.

Temporal Formula Patterns

The @ operator lets you reference any cell's historical value in any formula:

Period-over-period comparison

=B2 - B2@"2026-01-01"                    # Change since a specific date
=B2 / B2@"2026-01-01" - 1                # Fractional change (0.15 = 15% increase)

Aggregation over historical data

=SUM(B2:B100) - SUM(B2:B100@"2026-01-01")           # Total change across a range
=AVERAGE(B2:B100) - AVERAGE(B2:B100@"2025-12-31")    # Average shift year-over-year

Conditional analysis

=IF(B2 > B2@"2026-03-01", "Up", "Down")                          # Direction
=COUNTIF(MAP(B2:B20, LAMBDA(c, c > c@"2026-01-01")), TRUE)       # Count of cells that increased

Combining with spatial formulas

=DISTANCE(A1, A1@"2026-01-01")    # How far a tracked asset moved since Jan 1

Managing History

Click Manage History in the Time Warp panel to open the history modal. Three options:

• Delete All History -- removes all temporal data. Current cell values are preserved, but past snapshots are gone. Irreversible.
• Trim to Range -- keep only history within a selected time range. Use this to discard old data and reduce storage.
• Copy Snapshot to Now -- copies all cell values from a past point in time to the current state. The original history is preserved. Useful for reverting to a known-good state.

How It Works

Time Warp stores a timestamped record of every cell edit via the Yjs collaboration layer. When you use the @ operator in a formula, GeoSheet looks up what a cell's value was at the specified timestamp and uses that value in the calculation.

Time Warp operates at the workbook level -- when you scrub the timeline, all sheets in the workbook reflect the same moment. This means cross-sheet formulas always reference a consistent point in time.

When positioned at the latest timestamp, the grid is fully editable and new edits are recorded. When viewing a past timestamp, the grid is read-only with a visual indicator.

Practical Applications

• Budget tracking -- compare actual spend against budget at any point in the fiscal year
• Inventory monitoring -- see stock levels at any past date, identify when shortages began
• Sales pipeline -- track how deal values changed over a quarter
• Data quality auditing -- identify when incorrect data was entered and what it replaced
• Regulatory compliance -- maintain a complete audit trail of all data changes with timestamps
• Location tracking -- combine temporal formulas with spatial data to analyze how locations changed over time

Next Steps

• Time Warp -- full reference for Time Warp features, including history management and the timeline UI
• Formulas -- complete formula reference, including the @ temporal operator
• Using AI to Analyze Spreadsheet Data -- let Geovani build temporal analyses for you
• Getting Started -- new to GeoSheet? Start here