downloading a PGN


Where are you doing it from? Web or app?

MOBILE APP
I use the Chess.com Mobile App Release v4.1.7 (2133) as indicated under Parameters, French language, on Iphone 6.
Immediatly after finishing a game, I click the menu in the left lower corner (Nouvelle partie en 1 min / Ajouter un ami / Rejouer / Partager / Terminer contre l'ordinateur / Paramètres / Tourner l'échiquier / Désactiver les sons) , choose "Partager" then "Copier" to store it in "Notes" on the Iphone. This procedure is still the same. There is no menu to tick a box with/without time stamp.
On January 6th 2023 and more recently, my download has no time stamp.
So how can I get with timestamp as in the year 2022 on Mobile APP with my Iphone?
On January 1st 2023 and before, my download was with time stamp i.e. {0:24}. Note: The pgn did not contain the headers [TimeControl "60"] nor [EndTime "15:06:20 PST"] but time stamp.
APP ON COMPUTER Windows 10 with Opera Browser.
I put www.chess.com in my web browser and do a Login. I didn't find a Release Reference under Parameters.
Immediatly after finishing a game, I click the menu displaying the moves (On Top is written: Analyse / Nouvelle partie / Parties / Joueurs and "Coups" one line below ), choose in the last line the symbol "Télécharger" and a pop-up menu appears where you can choose PGN / Image / Animated Gif / Embed then a line below the FEN is displayed and one more line below the PGN is displayed.
at the end of this line is the clock symbol with a box you can tick. HERE IT IS POSSIBLE TO CHOOSE WITH OR WITHOUT TIME STAMP.
The download contains the pgn Headers
[TimeControl "60"]
[EndTime "15:06:20 PST"]
and displays as follows:
1. Nf3 {[%timestamp 1]} 1... b6 {[%timestamp 25]} 2. Nc3 {[%timestamp 5]} 2...
Bb7 {[%timestamp 4]} 3. h4 {[%timestamp 7]} 3... d6 {[%timestamp 16]}
There is a problem with {[%timestamp 1]} as this is not a useful information. Useful is the format with numbers indicating the remaining time i.e. {2:52} and next move {2:41}.
NOW A DOWNLOAD ON PC Menu Principal / Regarder / Mr Tattaglia
and downloading the live game (just finished) by the window:
Parties de MrTattaglia (19678)
and ticking the box next to the clock symbol for enabling the time stamp results in this perfect display:
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2023.01.15"]
[Round "-"]
[White "MrTattaglia"]
[Black "KostyaKornienko"]
[Result "1-0"]
[WhiteElo "3058"]
[BlackElo "3135"]
[TimeControl "15"]
[EndTime "0:54:17 PST"]
[Termination "MrTattaglia a gagné par échec et mat"]
1. b3 {[%clk 0:00:15]} 1... a5 {[%clk 0:00:15]} 2. Bb2 {[%clk 0:00:14.9]} 2...
a4 {[%clk 0:00:14.9]} 3. Qc1 {[%clk 0:00:14.8]} 3... axb3 {[%clk 0:00:14.8]}
That's fine, what I was used to and what I like.
Best greetings to the staff. They do great work!

The download contains the pgn Headers
[TimeControl "60"]
[EndTime "15:06:20 PST"]
and displays as follows:
1. Nf3 {[%timestamp 1]} 1... b6 {[%timestamp 25]} 2. Nc3 {[%timestamp 5]} 2...
Bb7 {[%timestamp 4]} 3. h4 {[%timestamp 7]} 3... d6 {[%timestamp 16]}
There is a problem with {[%timestamp 1]} as this is not a useful information. Useful is the format with numbers indicating the remaining time i.e. {2:52} and next move {2:41}.

and downloading the live game (just finished) by the window:
Parties de MrTattaglia (19678)
and ticking the box next to the clock symbol for enabling the time stamp results in this perfect display:
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2023.01.15"]
[Round "-"]
[White "MrTattaglia"]
[Black "KostyaKornienko"]
[Result "1-0"]
[WhiteElo "3058"]
[BlackElo "3135"]
[TimeControl "15"]
[EndTime "0:54:17 PST"]
[Termination "MrTattaglia a gagné par échec et mat"]
1. b3 {[%clk 0:00:15]} 1... a5 {[%clk 0:00:15]} 2. Bb2 {[%clk 0:00:14.9]} 2...
a4 {[%clk 0:00:14.9]} 3. Qc1 {[%clk 0:00:14.8]} 3... axb3 {[%clk 0:00:14.8]}
That's fine, what I was used to and what I like.

I don't know whether the %timestamp command is official, but I know that the command %emt for "elapsed move time" has been proposed (see https://www.enpassant.dk/chess/palview/enhancedpgn.htm)
So, I guess that the %timestamp value is an integer giving tenths of seconds, so to get the %clk value one has to start with the initial time and at each move subtract %timestamp / 10 and add the increment (if there is one).
I'm just writing a small python program that makes a PGN file from the web page of a game that has ended.
Because I have noticed that e.g. an aborted game cannot be "saved" or added to your library, and if you try to "share" the PGN all clock information is lost (and maybe also player's ratings).
So my script scans the HTML page for header information (players' names & rating & TimeControl) and the displayed move list to fetch the moves & time / move, and produces the corresponding PGN.
Let me know if you're interested.