backup:restore issue

date: invalid date '@1511088993_2017_11_19_10.1.0'
‣ 1511088993_2017_11_19_10.1.0_gitlab_backup.tar (created at )
date: invalid date '@1511064202_2017_11_19_10.1.0'
‣ 1511064202_2017_11_19_10.1.0_gitlab_backup.tar (created at )
date: invalid date '@1510459401_2017_11_12_10.1.0'
‣ 1510459401_2017_11_12_10.1.0_gitlab_backup.tar (created at )
date: invalid date '@1509854603_2017_11_05_10.1.0'
‣ 1509854603_2017_11_05_10.1.0_gitlab_backup.tar (created at )
date: invalid date '@1509281002_2017_10_29_9.5.5'
‣ 1509281002_2017_10_29_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1509249923_2017_10_29_9.5.5'
‣ 1509249923_2017_10_29_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1509249916_2017_10_29_9.5.5'
‣ 1509249916_2017_10_29_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1509249915_2017_10_29_9.5.5'
‣ 1509249915_2017_10_29_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1508645023_2017_10_22_9.5.5'
‣ 1508645023_2017_10_22_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1507435427_2017_10_08_9.5.5'
‣ 1507435427_2017_10_08_9.5.5_gitlab_backup.tar (created at )
date: invalid date '@1506830599_2017_10_01_9.5.5'
‣ 1506830599_2017_10_01_9.5.5_gitlab_backup.tar (created at )

Start by reproducing the backup restore listing with the filenames shown in the report and trace the command that parses their timestamps. Done means the backup entries display valid creation dates without the reported date errors.