The interpreted framerate shown in the Project Panel determines the time it takes to playback the footage. Usually, the metadata in the file sets the framerate so that one second equals one second. In other words, if you shoot footage with a camera at 60fps and it is interpreted as 60fps footage, one second of real-time equals one second of comp time (real-time).
Sometimes the metadata gets fouled up, and sometimes your system can't play that many frames per second. You change that by selecting the footage in the Project panel, going to the File/Interpret footage menu, or using the keyboard shortcut Alt/Option + Ctrl/Cmnd + g.
SWF files are notorious for screwing things up when you try to use them with anything but a web page. That is my personal opinion based on my experience with the format going back to when Macromedia took over the development of the format in the mid-'90s.
The recommended Animate to After Effects workflow is to import the Animate file. You will have all the layers and even the audio if you desire. Here is a video:
If you only have the SWF file to work with and know the precise timing difference, multiply the interpreted frame rate you see in the Interpret Footage panel by the current footage length divided by the desired duration of the footage. You can do the math directly in the Conform Frame Rate window.
If After Effects interprets your footage at 30 fps and the footage duration displayed in the Info section of the Project Panel is 0:00:07:15 and the running time in Animate is 0:00:16:00, try this workflow:
Select the "Conform Footage" option, double-click the value to select it all, press the right arrow key to move past the selection and then type * (7.5 * 16). The Duration and frame rate info to the right of the preview thumbnail will now show the correct duration and a new framerate. If you want the timeline to match frame for frame, the comp's frame rate must match the frame rate of the footage. If the new frame rate is not one of the standard video frame rates, you should leave the frame rates alone and time stretch or use time remapping to change the playback speed of the layer. If you choose to mismatch frame rates, explore all frame blending options to get the best-looking blended frames.