Convert datetime to numeric - preserve date format

I have a timetable with dates (datetime data type) in the format 'yyyy-MM-dd HH:mm'. I want to convert these to a numeric data type (double) but keeping the exact numbers of each date such that the datetime '2023-02-27 14:00' is converted to the double '202302271400'. The function yyyymmdd() allows me to do this for the date, but not the hour and minute, and none of the other built in functions to convert to datenumber seem to have this option. Thanks for any insights to this problem.

Answer 1

[Les Beckham]

Edited to work with datetime array vs a single datetime.

d = datetime(['2023-02-27 14:00'; '2023-02-27 15:00']) % test data - replace with your timetable 

d = 2×1 datetime array
   27-Feb-2023 14:00:00
   27-Feb-2023 15:00:00

s = string(d, 'yyyyMMddHHmm')

s = 2×1 string array
    "202302271400"
    "202302271500"

format long
% f = cellfun(@(s)sscanf(s, '%f'), s) % original method of converting to double
f = double(s) % An easier/cleaner method.  Thanks to Walter for reminding me about this.

f = 2×1

1.0e+11 * 2.023022714000000 2.023022715000000

compose('%.0f', f)

ans = 2×1 cell array
    {'202302271400'}
    {'202302271500'}

[Star Strider]

Just use the 'Format' for this, then convert it to a string or char array in either the same line or a separate assignment —

d = datetime(['2023-02-27 14:00'; '2023-02-28 15:00'], 'Format','yyyyMMddHHmm')

d = 2×1 datetime array
   202302271400
   202302281500

ds = string(d)

ds = 2×1 string array
    "202302271400"
    "202302281500"

dc = char(d)

dc = 2×12 char array
    '202302271400'
    '202302281500'

.

[Les Beckham]

I thought about that approach, but OP says that they already have the timetable. Who knows what format it was created with. Besides, they (for some unknown reason) wanted the result to be a float. Hence the sscanf call. I'll edit my answer to make it clear that the first line represents test data that will be replaced with the existing timetable.

[Star Strider]

There are single quotes around the desired ‘double’ result, so there may be a bit of confusion on the OP’s part in that regard.

[Les Beckham]

Good point. I saw that too, but they said "numeric type (double)".

Note that the compose command at the end was just to show that the values in f (the double result) are correct by printing them out -- since the exponential notation of the display of f makes it hard to tell if the decimal is in the right place.

[Elin Jacobs]

Thank you both, this works as intended. Sorry about the confusion on my single quotes around the double, I'll be more careful next time. Really appreciate your help!

[Walter Roberson]

You should not need sscanf of string array: just double() the string array

[Les Beckham]

Of course, thanks for reminding me of that. I've edited the answer to reflect this approach.

[Campion Loong]

@Walter Indeed. The question is meant for @Elin Jacobs. I mistook @Les Beckham to be the OP. Let me restate:

@Elin Although you can turn datetime into 'formatted numbers' with any of the above answers, would you mind elaborating on what makes you do that in the first place? Are you interfacing with another system that needs numerics representation of time in some way (like a database)?

[Elin Jacobs]

@Campion Loong You are right, I'm interfacing with a (poorly designed) database for a local weather station.

[Campion Loong]

@Elin Jacobs Thanks for confirming. That (unfortunately) makes sense.