Timestamp generation in Postman - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get the current timestamp in milliseconds.

Postman

var timestamp = [1]();

Drag options to blanks, or click blank then click option'

AtimeNow

BgetTime

Cnew Date

DDate.now

Attempts:

3 left

💡 Hint

Common Mistakes

Using new Date() without calling getTime() returns a Date object, not a timestamp.

Using a non-existent function like timeNow.

Date.now() returns the current timestamp in milliseconds since January 1, 1970.

2fill in blank

medium

Complete the code to convert a Date object to a timestamp in milliseconds.

Postman

var timestamp = new Date().[1]();

Drag options to blanks, or click blank then click option'

AgetTime

Bnow

CtoISOString

DvalueOf

Attempts:

3 left

💡 Hint

Common Mistakes

Using now() on a Date instance causes an error.

Using toISOString() returns a string, not a timestamp.

getTime() returns the timestamp in milliseconds from a Date object.

3fill in blank

hard

Fix the error in the code to get the current timestamp in seconds.

Postman

var timestamp = Math.floor(Date.[1]() / 1000);

Drag options to blanks, or click blank then click option'

Anow

BtimeNow

CgetTime

DcurrentTime

Attempts:

3 left

💡 Hint

Common Mistakes

Using getTime() as a static method of Date causes an error.

Using non-existent functions like timeNow or currentTime.

Date.now() returns the current timestamp in milliseconds. Dividing by 1000 and using Math.floor gives seconds.

4fill in blank

hard

Fill both blanks to create a timestamp string in ISO format and get its timestamp in milliseconds.

Postman

var isoString = new Date().[1]();
var timestamp = new Date(isoString).[2]();

Drag options to blanks, or click blank then click option'

AtoISOString

BgetTime

Cnow

DtoString

Attempts:

3 left

💡 Hint

Common Mistakes

Using now() instead of toISOString() for string conversion.

Using toString() returns a non-ISO string.

toISOString() converts the date to ISO string format.
getTime() converts the ISO string back to milliseconds timestamp.

5fill in blank

hard

Fill all three blanks to create a UNIX timestamp in seconds from a Date object.

Postman

var date = new Date();
var milliseconds = date.[1]();
var seconds = Math.[2](milliseconds / [3]);

Drag options to blanks, or click blank then click option'

AgetTime

Bfloor

C1000

Dnow

Attempts:

3 left

💡 Hint

Common Mistakes

Using now() on Date instance causes error.

Using Math.round instead of Math.floor changes the result.

Dividing by 60 or 100 instead of 1000.

getTime() gets milliseconds from the Date.
Math.floor() rounds down to whole seconds.
1000 converts milliseconds to seconds.

Practice

1. What does Date.now() return in Postman scripts?

easy

A. The current date as a string in format YYYY-MM-DD

B. The current time zone offset in minutes

C. The current timestamp in milliseconds since January 1, 1970

D. The current time in seconds since midnight

Solution

1. Step 1: Understand Date.now() function

   Date.now() returns the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC.

2. Step 2: Compare options with this definition

   Only The current timestamp in milliseconds since January 1, 1970 correctly describes this behavior as a timestamp in milliseconds.

3. Final Answer:

   The current timestamp in milliseconds since January 1, 1970 -> Option C

4. Quick Check:

   Date.now() = milliseconds timestamp [OK]

Hint: Remember: Date.now() gives milliseconds since 1970 [OK]

Common Mistakes:

• Thinking Date.now() returns a formatted date string
• Confusing milliseconds with seconds
• Assuming it returns time zone info

2. Which of the following is the correct way to save the current timestamp in a Postman environment variable?

easy

A. pm.environment.set('currentTime', Date.now());

B. pm.environment.get('currentTime', Date.now());

C. pm.environment.save('currentTime', Date.now());

D. pm.environment.store('currentTime', Date.now());

Solution

1. Step 1: Identify the correct method to set environment variables

   In Postman scripts, pm.environment.set(key, value) is used to save a variable.

2. Step 2: Check each option's method name

   Only pm.environment.set('currentTime', Date.now()); uses the correct method set with the right syntax.

3. Final Answer:

   pm.environment.set('currentTime', Date.now()); -> Option A

4. Quick Check:

   Use pm.environment.set() to save variables [OK]

Hint: Use pm.environment.set() to save variables [OK]

Common Mistakes:

• Using pm.environment.get() to save variables
• Using non-existent methods like save() or store()
• Forgetting to pass both key and value

3. What will be the output of this Postman test script snippet?

let start = Date.now();
pm.environment.set('startTime', start);
let end = Date.now();
pm.environment.set('endTime', end);
let duration = pm.environment.get('endTime') - pm.environment.get('startTime');
console.log(duration);

medium

A. A negative number due to subtraction order

B. Zero, because start and end are set at the same time

C. Undefined, because variables are not saved correctly

D. A positive number representing milliseconds elapsed between start and end

Solution

1. Step 1: Understand the timestamp capture

   start and end capture timestamps at two different moments, so end ≥ start.

2. Step 2: Calculate duration

   Subtracting start from end gives the elapsed time in milliseconds, which is positive or zero.

3. Final Answer:

   A positive number representing milliseconds elapsed between start and end -> Option D

4. Quick Check:

   duration = end - start ≥ 0 [OK]

Hint: Subtract start from end timestamps for elapsed time [OK]

Common Mistakes:

• Assuming start and end are identical
• Confusing subtraction order causing negative result
• Thinking variables are not saved properly

4. You wrote this Postman script to save a timestamp:

pm.environment.set('timeStamp', Date.now)

Why does this cause an error or unexpected behavior?

medium

A. Date.now is a function and needs parentheses to execute

B. pm.environment.set() cannot save numbers

C. The variable name 'timeStamp' is reserved

D. Date.now returns a string, not a number

Solution

1. Step 1: Check usage of Date.now

   Date.now is a function reference, not the timestamp itself.

2. Step 2: Identify missing parentheses

   To get the current timestamp, you must call the function with (), like Date.now().

3. Final Answer:

   Date.now is a function and needs parentheses to execute -> Option A

4. Quick Check:

   Call Date.now() with () to get timestamp [OK]

Hint: Always add () to call Date.now() function [OK]

Common Mistakes:

• Forgetting parentheses after Date.now
• Thinking pm.environment.set can't save numbers
• Assuming variable names cause errors

5. You want to measure the response time of an API request in Postman using timestamps. Which script correctly captures the start time before the request and calculates the duration after the response?

hard

A. In Tests: pm.environment.set('startTime', Date.now());In Pre-request Script: let duration = Date.now() - pm.environment.get('startTime');

B. In Pre-request Script: pm.environment.set('startTime', Date.now());In Tests: let duration = Date.now() - pm.environment.get('startTime');
pm.test('Response time', () => pm.expect(duration).to.be.below(2000));

C. In Pre-request Script: let duration = Date.now() - pm.environment.get('startTime');In Tests: pm.environment.set('startTime', Date.now());

D. In Tests: let duration = pm.environment.get('startTime') - Date.now();In Pre-request Script: pm.environment.set('startTime', Date.now());

Solution

1. Step 1: Capture start time before request

   The Pre-request Script runs before the API call, so saving startTime there is correct.

2. Step 2: Calculate duration after response

   The Tests script runs after the response, so subtracting startTime from current time gives elapsed time.

3. Final Answer:

   captures the start time before the request and calculates the duration after the response -> Option B

4. Quick Check:

   Pre-request sets start; Tests calculate duration [OK]

Hint: Set start time pre-request; calculate duration in tests [OK]

Common Mistakes:

• Setting start time after request instead of before
• Subtracting timestamps in wrong order
• Calculating duration before request runs