Date Math v1.7.0Daylight saving time transitions
Daylight saving time for a time zone: does it observe DST, the year's exact clock changes (UTC instant, local before/after), and whether a local time is valid, skipped (spring-forward gap, e.g. 02:30) or repeated (fall-back, happens twice). Use before scheduling jobs, alarms or meetings near clock changes.
MCP tool dst_checkHTTP POST /v1/dst25 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.
dst_check
result
{
"timezone": "America/New_York",
"year": 2026,
"observes_dst": true,
"standard_offset": "-05:00",
"dst_offset": "-04:00",
"transitions": [
{
"at_utc": "2026-03-08T07:00:00Z",
"local_before": "2026-03-08T02:00:00-05:00",
"local_after": "2026-03-08T03:00:00-04:00",
"offset_before": "-05:00",
"offset_after": "-04:00",
"change_minutes": 60,
"type": "clocks_forward"
}
],
"check": {
"local": "2026-03-08T02:30:00",
"status": "skipped",
"instants": [],
"resolved": "2026-03-08T03:30:00-04:00",
"note": "This local time does not exist: clocks jump forward 60 minutes. Most systems shift it forward to 03:30."
}
}
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 dst_check 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/dst \
-H "Content-Type: application/json" \
-d '{"timezone":"America/New_York","datetime":"2026-03-08T02:30"}'