sync: The start-time/end-time parameters, %Y-%m-%d and %H:%M:%S are strengthened for parameter verification

[YunhuiChen]

What happened:

When --start-time 2025-05-27 14:10:00 was used without quotation marks, no error was reported, but 14:10:00 did not take effect.

root@chaos-k8s-002:~/chenyunhui/juicefs# ll /juicefs1/1
-rw-r--r-- 1 root root 2 May 27 14:06 /juicefs1/1
root@chaos-k8s-002:~/chenyunhui/juicefs# ./juicefs sync /juicefs1/1 /juicefs1/2 --start-time 2025-05-27 14:10:00
2025/05/27 14:21:41.993170 juicefs[3377230] <INFO>: Prometheus metrics listening on 127.0.0.1:9567 [[email protected]:134]
2025/05/27 14:21:41.993818 juicefs[3377230] <INFO>: Syncing from file:///juicefs1/1 to file:///juicefs1/2 [[email protected]:1741]
 Scanned objects: 1/1 [==============================================================]  553.8/s used: 1.81822ms
Excluded objects: 0                 0.0/s
  Excluded bytes: 0.0 b (0 Bytes)   0.0 b/s
 Skipped objects: 0                 0.0/s
   Skipped bytes: 0.0 b (0 Bytes)   0.0 b/s
   Extra objects: 0                 0.0/s
     Extra bytes: 0.0 b (0 Bytes)   0.0 b/s
 Pending objects: 0                 0.0/s
  Copied objects: 1                 744.7/s
    Copied bytes: 2.0 b (2 Bytes)   1.5 KiB/s
  Failed objects: 0                 0.0/s
2025/05/27 14:21:41.995506 juicefs[3377230] <INFO>: Found: 1, excluded: 0 (0 B), skipped: 0 (0 B), copied: 1 (2 B), extra: 0 (0 B), failed: 0 [[email protected]:1676]

What you expected to happen:
jfs version:

root@chaos-k8s-001:~/chenyunhui/jfs-main# juicefs sync /jfs1/1 /jfs1/2 --start-time 2025-05-27 10:10:10
ERROR: This command accept at most 2 arguments but got [/jfs1/1 /jfs1/2 10:10:10]
USAGE:
juicefs sync [command options] SRC DST

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?

Environment:

• JuiceFS version (use juicefs --version) or Hadoop Java SDK version:
• Cloud provider or hardware configuration running JuiceFS:
• OS (e.g cat /etc/os-release):
• Kernel (e.g. uname -a):
• Object storage (cloud provider and region, or self maintained):
• Metadata engine info (version, cloud provider managed or self maintained):
• Network connectivity (JuiceFS to metadata engine, JuiceFS to object storage):
• Others:

[davies]

'2025-05-27' was supported as a format, so I'd say this is a feature.

We can add a warning for extra unused args.