Date & time tools
Timestamps, timezones, durations and cron schedules — convert and calculate dates and times.
Age Calculator
Calculate your exact age from your date of birth — years, months and days, next birthday countdown and total days lived. Free, private, in-browser.
Age encrypt
Encrypt small text into an ASCII-armored age ciphertext with a passphrase or native X25519 recipients.
Age Key Generator
Generate an age X25519 identity and its shareable age1 public recipient in your browser, or derive the recipient from an identity you already have.
Change Audio Speed (Keep Pitch)
Free online audio speed & tempo changer — speed up or slow down any track without changing the pitch. Set a factor, BPM ratio, or percentage in your browser.
Current UTC Time
See the current UTC date and time, updating live in your browser. No sign-up, runs offline.
Cron Next Run Times
Cron expression parser and next-run calculator — see upcoming run times in UTC with plain-English schedules, free and entirely in your browser.
CSV Date Normalizer
Normalize a CSV date column to ISO 8601, Unix time, SQL, or a custom pattern. Infers day-first vs month-first per column. Free, runs in your browser.
CSV to ICS
Paste a CSV of events and get an .ics calendar file to import into Google Calendar, Outlook or Apple Calendar. Free, private, runs in your browser.
Date Column Validator
Check every value in one CSV date column against a chosen format — ISO, US, EU, RFC 3339, or a custom pattern — with a per-row report of invalid dates.
Date Difference Calculator
Calculate the exact duration between two dates: years, months, days, hours, minutes and seconds, with leap years handled. Free, private, in-browser.
Date Format Normalizer
Paste text with dates in mixed formats and get them all rewritten to ISO 8601 or any format you pick, with the day/month order settled from the text. Free and private.
Deadline Countdown
Compute time remaining or overdue for dated tasks, label urgency, and sort the list by deadline in table, Markdown, JSON, or CSV format.
Extract Dates
Scan any text for dates and times and list them normalized to ISO 8601 — in your browser. Handles ISO, numeric, month-name, and clock formats. No upload.
ICS Merge & Dedupe
Merge several .ics calendar files into one and remove duplicate events by UID or start+title — all in your browser. Free, private, nothing uploaded.
ICS Parser
Parse .ics calendar files into JSON events with start/end, all-day status, location, attendees, organizer and RRULE recurrence. Runs in your browser.
ICS to CSV Converter
Convert an .ics calendar file to CSV in your browser — one row per event with summary, start, end, location and description. Free, private, nothing uploaded.
Log Timestamp Normalizer
Paste logs whose timestamps are in ISO-8601, epoch, syslog or Apache format and get one format, one timezone and the gap between events. Free and private.
One-Time Pad
Encrypt, decrypt, or generate true one-time pads locally: mod-26 letters, mod-10 digits, or bytewise XOR with hex/Base64 pads.
Date / Time Parser
Parse a date or time in almost any format — ISO 8601, RFC 2822, US/European dates — into year, month, day, weekday, ISO week and a canonical ISO 8601 value.
Period Predictor
Predict your next period start dates from your last period and cycle length, with ovulation estimates and fertile windows. Free, private, in-browser.
Seconds to HH:MM:SS
Convert seconds into HH:MM:SS, D:HH:MM:SS, ISO-8601, or human-readable duration text with optional fractional seconds. Runs locally in your browser.
Time Series Forecaster
Forecast a time series with exponential smoothing, Holt trend, damped trend, or Holt-Winters seasonality, including prediction intervals and accuracy metrics.
Time series generator
Generate deterministic synthetic time-series CSV, TSV, JSON or NDJSON with configurable trend, seasonality, noise, missing values and outliers.
Time-Series Resample
Resample timestamped CSVs to hourly, daily, weekly, monthly or yearly buckets with mean, sum, count, median, std or OHLC. Runs in your browser.
Time to Decimal Hours Converter
Convert HH:MM to decimal hours (1:30 → 1.5) and back for timesheets, payroll and billing — plus total minutes and seconds. Free, private, in-browser.
Timezone Converter & Meeting Planner
Convert a date and time across multiple timezones with correct DST handling and a 24-hour meeting planner grid. Full IANA database — free, private, in-browser.
Unix timestamp converter
Convert Unix timestamps (seconds, milliseconds, microseconds, nanoseconds) to UTC dates, or parse human-readable dates back to epoch timestamps. Free, private, no upload.