Preserving Original Timestamps in Robocopy: Essential Switches for File and Directory Time Retention

When I first used Robocopy to migrate files to a new storage drive, I noticed all file and directory timestamps were reset to the copy time. This behavior can cause issues when:

Tracking file creation history
Maintaining chronological organization
Running time-sensitive automation scripts

The solution lies in these critical switches:

robocopy source destination /COPY:DAT /DCOPY:T

Let's break down what each part does:

/COPY:DAT - Copies Data, Attributes, and Timestamps (D=Data, A=Attributes, T=Timestamps)
/DCOPY:T - Specifically handles directory timestamps (T=Timestamps)

For a robust copy operation that preserves all metadata:

robocopy C:\source D:\destination /MIR /COPY:DATSOU /DCOPY:T /R:1 /W:1 /ZB /NP /LOG:C:\copy.log

This command includes:

/MIR - Mirror mode (exact replica)
/COPY:DATSOU - Extended attributes (Security, Owner, Auditing info)
/ZB - Uses restartable mode with backup privilege
/R:1 /W:1 - Minimal retry/wait times

After copying, verify timestamps with PowerShell:

Get-ChildItem D:\destination -Recurse | Select FullName,CreationTime,LastWriteTime | Export-Csv -Path C:\timestamps.csv

For enterprise environments with strict compliance requirements:

robocopy \\server\share\source D:\archive /E /COPYALL /DCOPY:T /TEE /UNILOG+:C:\logs\archive_%date:~-4,4%%date:~-7,2%%date:~-10,2%.log

This adds:

/COPYALL - All file information (equivalent to /COPY:DATSOU)
/TEE - Output to console and log
/UNILOG+ - Unicode log with append mode

When migrating files between drives or servers using Robocopy, many developers encounter an unexpected behavior - all file and directory timestamps get reset to the current copy time. This can break workflows that rely on original creation/modification dates for version tracking, backups, or compliance purposes.

The solution lies in properly combining these essential switches:

robocopy source destination /COPY:DAT /DCOPY:T /R:1 /W:1 /MT:8

/COPY:DAT - Copies Data, Attributes, and Timestamps (D=Data, A=Attributes, T=Timestamps)

/DCOPY:T - Specifically handles directory timestamps (T=Timestamps)

For a complete mirror with timestamp preservation:

robocopy C:\\source D:\\backup /MIR /COPY:DAT /DCOPY:T /ZB /R:3 /W:5 /LOG:backup.log

Network copy with retries and timestamp preservation:

robocopy \\server1\share \\server2\backup /E /COPY:DATS /DCOPY:T /TEE /V /NP /MT:16

Missing /DCOPY:T when directory dates matter
Using /COPYALL instead of /COPY:DAT (can copy unnecessary security info)
Not combining with /MIR properly when mirroring

After copying, verify timestamps with:

dir /T:C /A-D
dir /T:C /AD

Or use PowerShell for more detailed verification:

Get-ChildItem -Recurse | Select-Object Name,CreationTime,LastWriteTime