FileZilla Client and Regional Time Zone Handling During FTP Transfers

Question

Time Zone Interoperability Gap in FileZilla FTP Transfers
FileZilla 3.5x and later versions include automatic timezone detection through the MLST command when the remote FTP server advertises timestamp timezone information. This client-side conversion adjusts displayed modification times according to the user's system timezone settings. However, the configuration interface provides no mechanism for manual timezone mapping when servers lack MLST support or report ambiguous timezone data.
The synchronization features rely on accurate timestamp comparison between local and remote files. When significant timezone differences exist and automatic detection fails, the client may incorrectly identify files as needing transfer, potentially causing unnecessary overwrites or missed updates during automated sync operations.
Current limitations include the absence of user-configurable timezone offsets in the Transfer Settings dialog and no fallback mechanism for legacy FTP servers that default to server-local time interpretation without timezone extensions.
Questions

Should FileZilla implement a user-configurable timezone mapping feature for servers that do not advertise timezone information through MLST?
How can the synchronization logic be improved to handle cross-timezone transfers more reliably when automatic timezone detection is unavailable?
Is it feasible to add manual timezone override controls to the Transfer Settings dialog to address inconsistent server implementations?

Tasadduq Burney · Answer

Answer
FileZilla should add a user-configurable timezone mapping feature for servers lacking MLST/MLSD support, and improve sync logic by normalizing timestamps to a common timezone (e.g., UTC) before comparison; manual override controls are technically feasible.
Likely explanation: Automatic timezone detection via MLST works only when the server advertises timezone data; without it, FileZilla may treat server-local timestamps as local time, causing sync mismatches.
Confirmed facts: FileZilla 3.5+ uses MLST/MLSD timestamps (typically UTC) and converts them to the client’s system timezone; on plain FTP servers without MLST, timestamps are parsed without explicit timezone info and may be interpreted as server-local time. No version‑independent manual offset field exists in Transfer Settings.

Connect to the FTP server and run an MLST/MLSD request; if the server replies with timezone information, automatic conversion applies.
If MLST is unavailable, request the server’s default timezone (e.g., via LIST parsing) or determine its local offset.
Manually set a timezone offset in FileZilla’s Site Manager (if the option exists) or note the limitation until a configuration UI is added.
For automated sync, configure the client to compare timestamps after converting both local and remote times to UTC, reducing false change detections.

Please confirm whether the target FTP server advertises MLST/MLSD support, as this determines the need for manual timezone mapping.

FileZilla Client and Regional Time Zone Handling During FTP Transfers

Time Zone Interoperability Gap in FileZilla FTP Transfers

Questions

1 answer

Answer

Your perspective belongs here.

0 question comments