Date Math v1.7.0Subscription renewal and proration dates
Subscription and contract date math: current billing period, next renewal, upcoming renewals, cancel-by date for a notice period, free-trial start, and day-based proration of a price. Month-end anchors stay at month end (Jan 31, Feb 28, Mar 31). Use for SaaS billing, renewals, cancellation deadlines and refunds.
MCP tool subscription_datesHTTP POST /v1/subscription25 free calls a day, then $0.001
Try it
Runs the real tool over MCP. Edit the arguments and run. Uses your daily free calls.
subscription_dates
result
{
"start": "2026-01-31",
"billing_start": "2026-01-31",
"interval": "month",
"interval_count": 1,
"as_of": "2026-03-10",
"status": "active",
"current_period": {
"number": 2,
"start": "2026-02-28",
"end": "2026-03-30",
"days": 31,
"days_elapsed": 10,
"days_remaining": 21
},
"next_renewal": "2026-03-31",
"next_renewal_weekday": "Tuesday",
"cancel_by": "2026-03-24",
"cancel_by_passed": false,
"upcoming_renewals": [
"2026-03-31"
],
"proration": {
"amount": 30,
"daily_rate": 0.967742,
"used": 9.68,
"unused": 20.32,
"ratio_unused": 0.677419
},
"note": "Renewals are measured from the first billing date, so month-end anchors stay at month end (Jan 31 -> Feb 28 -> Mar 31). Proration is by whole days as of the start of as_of."
}
The result shown before you run is a saved example response.
Use it from your agent
Add the MCP server once and your agent can call subscription_dates and the other 19 tools.
Claude Code
One command in your terminal.
claude mcp add --transport http date-math https://date-math.datemath.workers.dev/mcp
Any MCP client
Claude Desktop, Cursor, VS Code, Windsurf.
{
"mcpServers": {
"date-math": {
"url": "https://date-math.datemath.workers.dev/mcp"
}
}
}HTTP + x402
POST JSON; pay the 402 with any x402 client.
curl -X POST https://date-math.datemath.workers.dev/v1/subscription \
-H "Content-Type: application/json" \
-d '{"start":"2026-01-31","interval":"month","as_of":"2026-03-10","notice_days":7,"amount":30}'