Date & Timezone Drift Checker Learn more

Upload two exports, pick the date/time columns, and detect shifts (±days/hours) that cause totals to “move”. Runs locally in your browser.

Upload A

CSV / TSV / Excel (XLSX/XLS)

File:not loaded

Delimiter Date/time column

Upload B

CSV / TSV / Excel (XLSX/XLS)

File:not loaded

Delimiter Date/time column

Analyze

We compare day/hour distributions and test offsets to find the most likely shift.

Waiting for files

Test offsets

This is a heuristic. If the data is sparse or dates are inconsistent, use the “Top differences” table below to confirm.

Best offset

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Overlap (no shift)

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Higher is better

Overlap (best shift)

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Higher is better

Confidence

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Top bucket differences

After applying the best offset, these date buckets still drift the most.

Bucket:—

Bucket	A count	B count (shifted)	Delta

How to read results

Best offset is the shift that maximizes overlap of date buckets between A and B.

+24h / −24h often means a timezone conversion or date truncation is happening in one export.

DST sometimes shows up as +1h / −1h around daylight-saving transitions.

Date & Timezone Drift Checker