In recent years, large language models have demonstrated strong sequence modeling capabilities in time seriesforecasting (TSF) across domains such as energy, traffic, andmeteorology. However, these models fail to capture the periodicityinherent in timestamp sequences, and do not consider resolutionaware weighting when aggregating multi-scale predictions, limiting their ability to capture complex temporal dynamics. Toaddress these challenges, we propose a large language modelbased time series predictor that integrates relative-periodic jointtemporal encoding with multi-resolution dynamic aggregation,enabling more accurate and robust temporal modeling acrossdiverse time scales. Specifically, we design a relative-periodictime encoding that integrates periodic patterns extracted throughautocorrelation analysis with relative temporal features, thus capturing both periodicity and temporal dependencies. Meanwhile,we apply two-stage non-overlapping window pooling to producemulti-resolution inputs and feed them into the LLM for forecasting. To effectively utilize the impact of different resolutions,a resolution-aware dynamic weight aggregation mechanism isproposed to adaptively adjust the contribution of each temporalresolution in the final prediction. Finally, the experiment resultsdemonstrate that our predictor achieves consistent improvementsover AutoTimes on seven datasets: ETTh1 (MSE reduced by3.9%, MAE by 1.4%), ETTh2 (MSE reduced by 5.0%, MAEby 1.5%), ETTm1 (MSE reduced by 0.6%, MAE by 1.1%),ETTm2 (MSE reduced by 2.2%, MAE by 1.2%), ECL (MSEreduced by 3.1%, MAE by 2.0%), Weather (MSE reduced by6.0%, MAE by 3.7%), and Solar (MSE reduced by 3.6%, MAEby 2.5%). Our predictor not only advances temporal encodingand multi-resolution forecasting with LLMs, but also points tonew directions for their application in time series prediction.