Dates

new Date

The Date constructor captures the current moment down to milliseconds. Store the object when calendar fields are needed later.

const now: Date = new Date(); console.log(now.getFullYear());

Methods read year, month, and day from the stored moment. For raw speed, the numeric timestamp from the next sections is simpler.

toISOString

Logs need one stable order that sorts well and reads the same everywhere. The ISO method prints year first in UTC with millisecond precision.

const now: Date = new Date(); console.log(now.toISOString());

2026-03-14T09:30:00.000Z

Timestamps math

The now function returns milliseconds since the epoch as a plain number. Subtract two stamps to measure elapsed time without date objects.

const start: number = Date.now(); const stop: number = Date.now(); const elapsed: number = stop - start; console.log(elapsed);

Addition and subtraction are exact on these counts. Save stamps around slow work to find real costs instead of guessing.

Weekday names

The day method returns zero for Sunday through six for Saturday. Index a name table with that number to show friendly labels.

const names: string[] = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]; const today: Date = new Date(); console.log(names[today.getDay()] ?? "?");

The table order must start with Sunday to match the numeric contract. A fallback keeps the print safe even if the index ever surprises.

Next: Crypto random

Article author: Arthur Isaev