Time-stamp

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. What does a time-stamp on a transaction record show?

A The amount of money that was sent

B The date and time the record was made

2. When is the time-stamp added to a record?

A When the record is created

B Only after the record is deleted

3. Two transactions have different time-stamps. What can you work out from them?

A Which transaction happened first

B Which transaction was for more money

4. How do time-stamps help a ledger?

A They put the records in order

B They stop anyone from reading the records

5. A transaction was made at 14:32 on 3 March. Which part of the record is this?

A The sender's wallet

B The time-stamp

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1timestamp: 2026-02-03 14:05:09		ASORT records BY timestamp ASCENDING
2IF stamp_A < stamp_B THEN first ← A		BThe date and time added to a record to show exactly when it was made
3A time-stamp is added when the record is created, so it shows when the transaction was made		CThe transaction has no time-stamp, so nobody can tell when it was made or which happened first
4Sorting records by their time-stamps puts them in order, oldest first		DComparing time-stamps to find which record happened first
5transaction ← {from: Ava, to: Liam, amount: 50}		Erecord.timestamp ← NOW()
6timestamp: 2026-02-03 (date only)		FA time-stamp must include the time as well as the date, otherwise two transactions on the same day cannot be put in order

Definitions

time-stamp

Fill in the Blanks

Complete each line of code by filling in the missing parts.

transaction.timestamp ← ___()

IF t1.timestamp _ t2.timestamp THEN OUTPUT "t1 happened first" ENDIF

SELECT * FROM ledger ORDER BY timestamp ___

DECLARE timestamp : ____ timestamp ← NOW()

newRecord ← CreateRecord(amount) newRecord._________ ← NOW() APPEND(ledger, newRecord)

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A timestamp ← "Alice"

B amount ← 25

C record ← [timestamp, amount]

D OUTPUT record

Question 2

A sender ← "Ava"

B receiver ← "Ben"

C amount ← 10

D timestamp ← NOW() + 7

E OUTPUT timestamp

Question 3

A FUNCTION AddRecord(amount)

B record.amount ← amount

C record.time ← "unknown"

D RETURN record

E ENDFUNCTION

Question 4

A timeA ← "09:15"

B timeB ← "09:20"

C IF timeA > timeB THEN

D OUTPUT "A happened first"

E ENDIF

Question 5

A timeA ← "10:05"

B timeB ← "10:02"

C IF timeB < timeA THEN

D OUTPUT "A was made first"

E ENDIF

Answer Key

Time-stamp

Section A: Quick Questions

B — The date and time the record was made

A — When the record is created

A — Which transaction happened first

A — They put the records in order

B — The time-stamp

Section B: Match the Pairs

timestamp: 2026-02-03 14:05:09 → The date and time added to a record to show exactly when it was made

IF stamp_A < stamp_B THEN first ← A → Comparing time-stamps to find which record happened first

A time-stamp is added when the record is created, so it shows when the transaction was made → record.timestamp ← NOW()

Sorting records by their time-stamps puts them in order, oldest first → SORT records BY timestamp ASCENDING

transaction ← {from: Ava, to: Liam, amount: 50} → The transaction has no time-stamp, so nobody can tell when it was made or which happened first

timestamp: 2026-02-03 (date only) → A time-stamp must include the time as well as the date, otherwise two transactions on the same day cannot be put in order

Section C: Definitions

time-stamp — The date and time added to a record when it is created, showing when it was made. It puts records in order and shows which happened first.

Section D: Fill in the Blanks

transaction.timestamp ← NOW()

IF t1.timestamp < t2.timestamp THEN
    OUTPUT "t1 happened first"
ENDIF

SELECT * FROM ledger ORDER BY timestamp ASC

DECLARE timestamp : DATE
timestamp ← NOW()

newRecord ← CreateRecord(amount)
newRecord.timestamp ← NOW()
APPEND(ledger, newRecord)

Section E: Spot the Error

A — A time-stamp must be the date and time the record was made, so it should be set with NOW(). A person's name is not a time-stamp.

D — The time-stamp must show exactly when the record was created. Adding 7 to it changes the time, so it should be timestamp ← NOW().

C — The time-stamp is added when the record is created and must hold the real date and time. It should be record.time ← NOW(), not the text "unknown".

C — The earlier time-stamp shows which record happened first. A (09:15) is earlier than B (09:20), so the test should be timeA < timeB.

D — The condition checks that B's time-stamp is earlier than A's, so B was made first. The output should say "B was made first".