Cron next runs

Parse a 5-field cron expression and return the next N run times (UTC).

Input

Field	Type	Description
expr *	string	5-field cron: minute hour day-of-month month day-of-week
count	number	How many upcoming runs (1-20, default 5)
from	any	Start time (epoch/ISO, default now)

Example output

{
  "expr": "*/15 9-17 * * 1-5",
  "next": [
    "2026-06-11T09:00:00.000Z"
  ]
}

Try it - see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/cron-next \
  -H "Content-Type: application/json" \
  -d '{"expr":"*/15 9-17 * * 1-5","count":5}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/cron-next", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "expr": "*/15 9-17 * * 1-5",
    "count": 5
  }),
});

No wallet? Pay with compute

This is a pure-CPU tool, so an agent without a wallet can pay with proof-of-work instead of USDC: fetch a challenge, solve the sha256 puzzle (16 leading zero bits - a fraction of a second of CPU, no money, no AI tokens), and resend with the X-Pow-Solution header.

import { createHash } from "node:crypto";
const lz = (b) => { let t = 0; for (const x of b) { if (!x) { t += 8; continue; } t += Math.clz32(x) - 24; break; } return t; };
const c = await (await fetch("https://agent402.tools/api/pow/challenge?slug=cron-next")).json();
let n = 0;
while (lz(createHash("sha256").update(c.challenge + ":" + n).digest()) < c.difficulty) n++;
await fetch("https://agent402.tools/api/cron-next", { method: "POST", headers: { "X-Pow-Solution": c.token + ":" + n, "Content-Type": "application/json" }, body: JSON.stringify({"expr":"*/15 9-17 * * 1-5","count":5}) });

Part of these workflows

This tool is one step in 2 curated multi-tool workflows - agents can fetch the whole sequence as an MCP prompt or call https://agent402.tools/api/skill-packs/{slug}/prompt.

• Meeting scheduler - Schedule a meeting across timezones without the round-tripping. Convert a proposed UTC slot into every attendee's local time, verify it lands on a working day for each, project the end time, generate human-readable countdowns, expand recurring rules, and report exactly how far out the slot sits - in one deterministic pass.
• Timezone planner - Time zone conversion, business day calculation, and cron schedule preview - scheduling in one pass.

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