OnlineCyberTools MCP (280+ filterable tools)

time_age_calculator

Read-onlyIdempotent

Calculate exact age from a birth date to any reference date, or compute the years, months, and days between two dates. Get breakdowns, totals, and next birthday details.

Instructions

Age and Date-Span Calculator. Compute exact age or elapsed time from a birth date to a reference date (defaults to today, UTC), in proleptic-Gregorian calendar math. operation "compute" returns a years/months/days breakdown plus totals (months/weeks/days/hours/minutes/seconds), next-birthday details, the day of the week you were born, and decorative western/chinese zodiac; operation "yearsBetween" returns only the non-negative years/months/days/totalDays span between two dates. Use this for age and birthday math; use time_date_difference instead for business-day counts or for adding/subtracting a duration from a date. Runs locally via the same JS logic the page uses: read-only, non-destructive, offline-capable, rate-limited (60 req/min anonymous), no auth. Results are wrapped as operation plus data.

Input Schema

TableJSON Schema

Name	Required	Description
`operation`	Yes	"compute": age/elapsed time from a birth date (needs birthYear/Month/Day; optional asOf). "yearsBetween": span between two dates (needs from and to*).
`birthYear`	No	Birth year (proleptic Gregorian). Required when operation is compute.
`birthMonth`	No	Birth month 1-12. Required when operation is compute.
`birthDay`	No	Birth day 1-31; must be a real calendar date. Required when operation is compute.
`asOfYear`	No	Reference year for compute. Omit all asOf* to use today (UTC).
`asOfMonth`	No	Reference month 1-12 for compute. Omit all asOf* to use today (UTC).
`asOfDay`	No	Reference day 1-31 for compute. Omit all asOf* to use today (UTC).
`fromYear`	No	Start year. Required when operation is yearsBetween.
`fromMonth`	No	Start month 1-12. Required when operation is yearsBetween.
`fromDay`	No	Start day 1-31. Required when operation is yearsBetween.
`toYear`	No	End year. Required when operation is yearsBetween.
`toMonth`	No	End month 1-12. Required when operation is yearsBetween.
`toDay`	No	End day 1-31. Required when operation is yearsBetween.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`operation`	No	The operation that was run, echoed back (compute or yearsBetween).
`data`	No	Result payload; shape depends on operation.

Schema Changelog

Changes observed during successful MCP inspections.

Changed23 schema fields changedv0.5.1Jun 3, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / asOfDay

Added value: +{
+  "description": "Reference day 1-31 for compute. Omit all asOf* to use today (UTC).",
+  "maximum": 31,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / asOfMonth

Added value: +{
+  "description": "Reference month 1-12 for compute. Omit all asOf* to use today (UTC).",
+  "maximum": 12,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / asOfYear

Added value: +{
+  "description": "Reference year for compute. Omit all asOf* to use today (UTC).",
+  "maximum": 9999,
+  "minimum": -9999,
+  "type": "integer"
+}

addedInput schema / properties / birthDay / description

Added value: +"Birth day 1-31; must be a real calendar date. Required when operation is compute."

addedInput schema / properties / birthDay / maximum
```
Added value: +31
```
addedInput schema / properties / birthDay / minimum
```
Added value: +1
```

addedInput schema / properties / birthMonth / description

Added value: +"Birth month 1-12. Required when operation is compute."

addedInput schema / properties / birthMonth / maximum
```
Added value: +12
```
addedInput schema / properties / birthMonth / minimum
```
Added value: +1
```

addedInput schema / properties / birthYear / description

Added value: +"Birth year (proleptic Gregorian). Required when operation is compute."

addedInput schema / properties / birthYear / maximum
```
Added value: +9999
```
addedInput schema / properties / birthYear / minimum
```
Added value: +-9999
```

addedInput schema / properties / fromDay

Added value: +{
+  "description": "Start day 1-31. Required when operation is yearsBetween.",
+  "maximum": 31,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / fromMonth

Added value: +{
+  "description": "Start month 1-12. Required when operation is yearsBetween.",
+  "maximum": 12,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / fromYear

Added value: +{
+  "description": "Start year. Required when operation is yearsBetween.",
+  "maximum": 9999,
+  "minimum": -9999,
+  "type": "integer"
+}

addedInput schema / properties / operation / description

Added value: +"\"compute\": age/elapsed time from a birth date (needs birthYear/Month/Day; optional asOf*). \"yearsBetween\": span between two dates (needs from* and to*)."

addedInput schema / properties / operation / enum

Added value: +[
+  "compute",
+  "yearsBetween"
+]

addedInput schema / properties / toDay

Added value: +{
+  "description": "End day 1-31. Required when operation is yearsBetween.",
+  "maximum": 31,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / toMonth

Added value: +{
+  "description": "End month 1-12. Required when operation is yearsBetween.",
+  "maximum": 12,
+  "minimum": 1,
+  "type": "integer"
+}

addedInput schema / properties / toYear

Added value: +{
+  "description": "End year. Required when operation is yearsBetween.",
+  "maximum": 9999,
+  "minimum": -9999,
+  "type": "integer"
+}

changedInput schema / required

Previous value: -[
-  "operation",
-  "birthYear",
-  "birthMonth",
-  "birthDay"
-]New value: +[
+  "operation"
+]

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "data": {
+      "description": "Result payload; shape depends on operation.",
+      "properties": {
+        "asOf": {
+          "description": "Reference date as year/month/day/isoDate (compute only).",
+          "type": "object"
+        },
+        "birth": {
+          "description": "Birth date as year/month/day/isoDate (compute only).",
+          "type": "object"
+        },
+        "bornOnDayOfWeek": {
+          "description": "Weekday name the birth date fell on (compute only).",
+          "type": "string"
+        },
+        "days": {
+          "description": "Remaining days after months.",
+          "type": "integer"
+        },
+        "from": {
+          "description": "Start date as year/month/day/isoDate (yearsBetween only).",
+          "type": "object"
+        },
+        "months": {
+          "description": "Remaining whole months after years (0-11).",
+          "type": "integer"
+        },
+        "nextBirthday": {
+          "description": "Upcoming birthday info (compute only): isoDate, daysUntil, dayOfWeek.",
+          "type": "object"
+        },
+        "to": {
+          "description": "End date as year/month/day/isoDate (yearsBetween only).",
+          "type": "object"
+        },
+        "totalDays": {
+          "description": "Total elapsed days between the two dates.",
+          "type": "integer"
+        },
+        "totalHours": {
+          "description": "Total elapsed hours (compute only).",
+          "type": "integer"
+        },
+        "totalMinutes": {
+          "description": "Total elapsed minutes (compute only).",
+          "type": "integer"
+        },
+        "totalMonths": {
+          "description": "Total elapsed whole months (compute only).",
+          "type": "integer"
+        },
+        "totalSeconds": {
+          "description": "Total elapsed seconds (compute only).",
+          "type": "integer"
+        },
+        "totalWeeks": {
+          "description": "Total whole weeks elapsed (compute only).",
+          "type": "integer"
+        },
+        "years": {
+          "description": "Whole years in the calendar breakdown.",
+          "type": "integer"
+        },
+        "zodiacChinese": {
+          "description": "Decorative chinese zodiac animal by Gregorian year (compute only).",
+          "type": "string"
+        },
+        "zodiacWestern": {
+          "description": "Decorative western tropical zodiac sign (compute only).",
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "operation": {
+      "description": "The operation that was run, echoed back (compute or yearsBetween).",
+      "type": "string"
+    }
+  },
+  "type": "object"
+}

First observedv0.1.0May 31, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Adds context beyond annotations: read-only, non-destructive, offline-capable, rate-limited, no auth. No contradictions with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Well-structured and front-loaded, but slightly verbose with repeated 'operation' phrases. Still efficient.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers all aspects: purpose, operations, parameters, usage, behavioral traits. Output schema exists, so return values not needed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so description adds limited value on parameters. It hints at required params per operation but doesn't elaborate beyond schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool computes age or elapsed time with two operations, and distinguishes from sibling time_date_difference.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly says when to use this tool (age/birthday math) and when to use time_date_difference instead, plus mentions local execution and rate limits.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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