Daylight Hours

Overview

Returns detailed information including day of year, sunrise/sunset times, and formatted daylight duration, perfect for solar energy, agriculture, and travel applications.

Live Test Daylight Hours Source →

Formula

One function covers the whole catalog: the first argument names the source, the rest are its inputs, and the "field" pair says which single value lands in the cell. Formulas covers the grammar that applies to all of them.

=VERVE("daylightduration", A2, B2, "field", "description")

A2 holds latitude, B2 holds longitude. Arguments go in that order — the same order as the table below.

With literal values

Nothing has to come from a cell — typed values work the same way.

=VERVE("daylightduration", 40.7128, -74.006, "field", "description")

Inputs

Required inputs are positional, in the order below. Everything else is passed as a "name", value pair after them — the same shape as SUMIFS. Premium inputs are accepted on every plan but only take effect on plans that include them.

Input	Type	Where it goes	Description
`latitude`Required	number	argument 2 (A2)	Latitude of the location range -90–90
`longitude`Required	number	argument 3 (B2)	Longitude of the location range -180–180
`date`OptionalPremium	string	"date", value	Date in YYYY-MM-DD format (defaults to today) date

Passing an option

=VERVE("daylightduration", A2, B2, "date", "2024-06-21")

What lands in your sheet

The "field" pair is what makes the formula resolve to one cell. Its value is a dot-path from the table below, so swapping it is how you pull a different value — one formula per column.

Seeing everything at once

Drop the "field" pair and the formula returns the whole response instead: two columns, field name on the left and value on the right, spilling from the cell you typed in.

=VERVE("daylightduration", A2, B2)

Good for exploring, not for filling down

The second row's table would land on top of the first's, and every cell after the first reads #REF! (#SPILL! in Excel). Keep one per sheet, or name a field, and leave the cells below and to the right empty.

Response fields

Paths are relative to data. Each one is exactly what the "field" pair accepts, so swapping it is how you pull a different value into a cell. On a plan without a Premium field the cell reads #PREMIUM(field) rather than a value, so a locked field never looks like a real answer.

Use as "field"	Type	Example cell value	Description
`date`	string	`2024-06-21`	The requested date for daylight calculation
`location`	object	`{…}`
`location.latitude`	number	`40.7128`	Location latitude coordinate used for calculation
`location.longitude`	number	`-74.006`	Location longitude coordinate used for calculation
`condition`Premium	string	`Normal`	Special solar condition at location, e.g., polar day
`description`	string	`Standard sunrise and sunset`	Human-readable description of solar conditions
`sunrise`	string	`09:25:09`	Sunrise time in HH:MM:SS format
`sunset`	string	`24:30:44`	Sunset time in HH:MM:SS format
`daylight_duration`	object	`{…}`
`daylight_duration.total_minutes`Premium	number	`905.58`	Total daylight duration in minutes with decimal precision
`daylight_duration.hours`	number	`15`	Daylight hours component as integer
`daylight_duration.minutes`	number	`5`	Remaining daylight minutes component after hours
`daylight_duration.formatted`	string	`15:05:00`	Formatted daylight duration as HH:MM:SS string
`day_of_year`	number	`173`	Julian day number of the year, one to 366
`is_valid`	boolean	`true`	Indicates whether calculation is valid for location

Filling a whole column

Both platforms make one batched call for a column rather than one request per cell, and both cost the same — 2 credits per row looked up. How you write it differs, because the two runtimes batch at different points.

Rows 2–100 in one call

=VERVE("daylightduration", A2:A100, B2:B100, "field", "description")

In Google Sheets, give the arguments ranges and the answers spill down from the cell you typed in. Custom functions there run synchronously and in isolation, so dragged cells cannot be coalesced — the range form is how a column becomes one call. The "field" pair is required here: a per-row two-column table has nowhere to spill. Use a full column per input (A2:A100, not A2) — a single-cell reference is read as row 1 only and the rest of the column comes back blank.

In Excel, type the formula once and fill down — no range form and none needed, because its runtime is asynchronous and the add-in coalesces the calls a fill produces into a single batched request. Do not hand VERVE.CALL a range: Excel flattens it into positional arguments, so A2:A100 arrives as a hundred separate arguments and the cell reads #ERR rather than filling.

Either way, column A holds your latitude values and the answers land beside them, one row each, blank rows skipped.

When a cell doesn't fill

A failed lookup returns readable text starting with #ERR rather than a spreadsheet error, because Excel cannot show a custom message on a real error — you would get a bare #VALUE! with no reason. The trade-off is that IFERROR() will not catch it; test with LEFT(cell, 4) = "#ERR" instead. Error handling covers the rest.

Cell reads	What happened
`#ERR Not connected`	No API key saved. Open the side panel and connect your account.
`#ERR Replace <name> with a cell or value`	A preview formula was copied as-is. Swap the placeholder for a cell reference.
`#ERR No "x" in daylightduration`	An option name this source does not take. The message lists the ones it does.
`#ERR No data point "…"`	The `"field"` path is not in the response. Check it against the table above.
`#PREMIUM(field)`	The field exists but your plan does not include it.
`#ERR Out of credits`	The cycle's credits are spent. Usage resets on your billing date.

Before the formula works

The add-in reads the API key you saved once in the side panel — the key never goes in the formula, so a shared sheet does not leak it and a collaborator without access simply sees the last calculated values.

Install the add-in for Google Sheets or Excel.
Open the side panel and sign in, or paste a key from your dashboard.
Type the formula above into any cell.

Use cases

Solar Optimization: Calculate daylight hours for solar panel optimization and energy production forecasting based on geographic location
Activity Planning: Plan outdoor activities and events based on accurate sunset and sunrise times for any location and date
Weather Apps: Build weather and astronomy applications with precise daylight duration calculations and solar position data
Photography Scheduling: Schedule photography sessions based on golden hour timing, blue hour, and optimal natural lighting conditions

Other ways to use Daylight Hours

Set up Daylight Hours on VerveSheets, or reach the same source a different way. Your VerveSheets account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.VerveKit →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →