Understanding Developer Days and Developer Months in Reports Collection

Last updated: October 2, 2026

Your downloadable Cost Capitalization report includes four effort columns. This article explains what each one means, how Developer Months are calculated, and how to reconcile the numbers.

The Four Effort Columns

Column	What it means
`fte_developer_days`	Total effort attributed to this person and work item, in days
`capitalization_developer_days`	The portion of that effort that's capitalized, after your capitalization % and date windows are applied
`fte_developer_months`	`fte_developer_days` expressed as a fraction of a working month
`capitalization_developer_months`	`capitalization_developer_days` expressed as a fraction of a working month

Working days means the business days in the calendar month (Monday–Friday), plus any additional days that person actually worked outside of those — weekends or holidays where we observed activity.

This means the divisor is specific to each person and each month.

In a month with 22 business days, someone who worked two Saturdays has a divisor of 24, while a teammate who didn't, has 22. You will therefore not be able to reproduce the column by dividing every row by the same number.

Whether non-business activity days are included depends on your organization's Basic Setting: How to calculate developer-months under Settings > DevFinOps. The options are business days in the month, calendar days in the month, and business days in the month plus any days worked outside of business days. Your Span admin can tell you which is configured for your account.

The value is capped at 1.0, since a person can't register more than one developer month within a single month.

Why some rows show 0 Developer Months

Developer Months are displayed rounded to two decimal places, so any value below 0.005 shows as 0.

For example, a row with capitalization_developer_days of 0.08 in a 24-working-day month works out to 0.0033 developer months. That's a real value — just smaller than two decimal places can display.

Nothing is being dropped from your totals. The fte_developer_days column holds the precise figure, and these rows still contribute fully to your aggregate costs. The zero only affects how that one row displays in the Developer Months column.

Small per-row values are completely normal. Each row represents one person's effort on one work item in one month, so when someone touches several epics their time naturally divides into many small slices.

Reconciling the report

Our recommendation: reconcile from the fte_developer_days columns, and divide once at the level you care about.

Today, each row's Developer Months value is rounded on its own, so adding that column up across many rows accumulates a little rounding along the way. Twenty rows that each round up by 0.004 will overstate the total by roughly 0.08 — occasionally enough to make a person-month look slightly above 1.00 even when the precise calculation sits at or below it.

To check one person's total for a month:

Sum capitalization_developer_days for that person and month.
Divide by their working days for that month, once.

That gives you the exact figure. The same approach works for epic-level and team-level totals.