Allowing a wider range of input formats for interview time

29 October 2021 • Tags: interviews

A lot of users get an error message when they enter an interview time. A significant number of users have to try again more than once.

Most of the errors occur because we do not allow users to:

• use a 24 hour format such as ‘13:15’ instead of ‘1:15pm’
• make mistakes like leaving spaces between hours and minutes
• leave the interview time field empty
• enter both a start and end time in the field, for example ‘1pm - 2pm’

Data analysis #

We looked at the errors which users are making. From the launch of the interview feature to 22 October 2021:

• 4114 interviews have been set up
• 401 errors have been triggered

Out of the 401 errors, 291 relate to the time. Out of the 291 errors:

• 22 are due to leaving the field empty
• 269 are due to the format not being accepted

Out of the 269 errors due to the format not being accepted:

• 95 used a 24 hour clock format, for example ‘10:30’
• 56 had an extra space, dot or colon, for example ‘9:30 am’
• 53 used a 3 digit time without am or pm, for example ‘9:30’
• 13 had a contradictory mixed format, for example ‘17:15pm’
• 10 omitted a colon or dot, for example ‘930am’
• 4 used a semicolon, for example ‘9;30am’
• 6 had a double digit hour without am or pm, for example ‘10’ or ‘13’
• 33 were not accepted for other reasons, such as entering ‘12noon’, ‘12om’, ‘2pm - 3pm’ or ‘tbc’

While most users get an error only once, many get an error multiple times.

Number of errors	Number of users
1	102
2	46
3	26
4	11
5	2
6	5
7	1
14	1
15	1

What we changed #

We made changes to allow a wider range of formats. These changes would have prevented 220 of the 269 time format errors we found in our analysis.

We also changed the hint text to reflect that we allow the use of a 24 hour format. At the same time we changed the field label.

Accepting a 24 hour format #

We currently accept a 12 hour format such as ‘9am’ or ‘2:30pm’. We do not accept a 24 hour format such as ‘09:00’ or ‘14:30’.

We’ll now accept both formats.

We will not allow mixed formats for times in the afternoon, even if they’re consistent such as ‘22:15pm’. This is due to a limitation of the technical solution being used to validate times.

Allow dots and other characters #

We do not currently accept minor mistakes such as using ‘a.m.’ instead of ‘am’. We also do not accept dots or spaces instead of colons, such as ‘3.15pm’.

In most cases we will now allow the use of colons, dots, spaces or no punctuation at all, as long as the value can be interpreted as a 12 or 24 hour format.

An exception is if a user includes a space within ‘a m‘ or ‘p m’. We will not accept this due to a limitation of the technical solution being used to validate times.

Changing the label and hint text #

The label for the input is currently ‘time’. We changed it to ‘start time’ to help users understand that they cannot enter a range.

The hint text currently says ‘For example, 9am or 2:30pm - enter 12pm for midday’. We changed it to ‘For example, 2pm or 14:30’ to show we also accept a 24 hour format.

We removed the note about midday because it allows us to have very short and clear hint text.

There’s no evidence that users accidentally enter midnight when they mean midday. This could be because the current hint text is functioning well, but we think that playing back the time on the ‘check answers’ page is enough.

We’ll reconsider this if we find that a significant number of users are making a mistake.

Examples of acceptable and unacceptable time formats #

These examples help to explain the rules we’ll follow. They do not include every possible combination of numbers, letters and punctuation.

Examples of acceptable time formats #

Input	Output	Why we accept this input
05:15	5:15am	24 hour format
0515	5:15am	24 hour format, no separator
05.15	5:15am	24 hour format
05 15	5.15am	24 hour format, ignore space
5:am	5am	12 hour format, ignore colon
5.am	5am	12 hour format, ignore dot
515am	5:15am	12 hour format, no separator
515.am	5:15am	12 hour format, no separator, ignore dot
515a.m.	5:15am	12 hour format, no separator, ignore dots
515a.m	5:15am	12 hour format, no separator, ignore dots
515 am	5:15am	12 hour format, no separator, ignore space
5 15am	5:15am	12 hour format, no separator, ignore space
5 15 am	5:15am	12 hour format, no separator, ignore space
5 15	5:15am	24 hour format, no separator, no leading zero
5:15	5:15am	24 hour format, no leading zero
515	5:15am	24 hour format, no separator, no leading zero
0515pm	5:15pm	12 hour format, no separator, ignore leading zero
05:15am	5:15am	12 hour format, ignore leading zero
05.15am	5:15am	12 hour format, ignore leading zero
5:00am	5am	12 hour format
13	1pm	24 hour format, no minutes
5	5am	24 hour format, no minutes, no leading zero
00	12am	24 hour format, no minutes, no trailing zeros
05	5am	24 hour format, no minutes
12	12am	24 hour format, no minutes
5.	5am	24 hour format, no minutes, no leading zero, ignore dot

Examples of unacceptable time formats #

Input	Why we do not accept this input
0	Not 12 hour or 24 hour format
0am	Not 12 hour or 24 hour format
00am	Not 12 hour or 24 hour format
9;15am	Uses semicolon
17:15am	Not a 12 hour or 24 hour format
1715am	Not a 12 hour or 24 hour format
515a m	Users have never got an error due to this and it’s extra work to make the service accept it
17:15pm	Users have got this error 12 times but it’s extra work to make the service accept it
17pm	Not a 12 hour or 24 hour format
8am-9am	We do not accept ranges
tbc	Not 12 hour or 24 hour format
12noon	Not 12 hour or 24 hour format

Further considerations #

In future, we’ll consider:

• making the interview time field optional or having a ‘to be confirmed’ option
• giving users the choice not to email the candidate when setting up or changing the details of an interview
• letting users enter an interview end time or interview duration
• accepting a mixed format, for example 17:15pm or 13pm
• accepting a semicolon, for example 5;15pm
• assuming that the digits 1 to 6 indicate the afternoon if the time does not include ‘am’ or ‘pm’ but is not in 24 hour format, for example ‘3’

Setting up an interview#

Setting up an interview - check answers#

Changing interview details#

Changing interview details - check answers#